360 magnum. 1 piston lower in cylinder??

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ham...With this info it sounds like a balanced kit and fresh bores would be the best bet and that will run into some serious coin. Still need cam, intake, etc.
You hit the nail with my intended use. Spirited Back roads driving, some stoplight antics and cruise nights. Would also like to do some distance driving a couple times a year (Skyline drive perhaps).
Current set-up is a 72 Satellite 3600# with LA 360 .030 flat tops, pocket ported and milled smog heads, thin head gaskets, Crane RV cam HV-260-2 I believe. Eddy performer and 600 carb. 904, 2600 stall, 8.25 2.71 ( I know!!). Tires are 26" tall. Car also has ac/ps and 4 wheel disc. I know you didn't ask but also HD springs, 18 inch wheels, .96? front and std rear sway bars, tubular upper and boxed lower CA, frame connectors and full poly bushings. Fun car. No torque.
My plan was shooting for stock bore magnum, EQ, LA front, Crosswinds intake and SG 3.55's. Comp recommend roller XR264 cam with this set-up. I also have a 518 for the near future. Possibly Holley or Fitech when funds become available.
 
Just weigh the big and small end of the rod, because you need to match those weights with the new one by grinding some off each end.maybe.

Cold it will press out fine, use the right arbor/or smaller pin. When you press the new piston... You'll want to put the pin in the freezer and heat the small end of the rod before pressing the new pin through the piston and into the new rod.

Rod heater would be nice.
 
Just found a good piston/pin assembly for a 1996 (mine is 2001) on ebay. If the crank and bore is good i can match weight of used piston assembly to my bent and swap on my rings.
 
OK.... makes sense for your roads and neighborhoods, and sounds like a LOT of fun. Keeping a wider torque band is really good for that.....as you seem to have found out. I hate to spend your money for you LOL.... but that stroker idea seems to be a good thought for that heavier car in that kind of use. (BTW, my racing background is rally, and a wide torque band is needed there too. Ditto for our spirited driving around the southern Appalachians...I can give you some awesome roads to drive when you get down this way again. Look at US250 west of Staunton VA over to the Elkins WV area. Make sure your brakes are 100%!)

A big part of 'no torque' is what you are starting with in that low SCR LA360. The Magnum is a step in the right direction but it can still stand to have more CR for your use. Example: My son and I built his 340 in his '65 Cuda for the same type of use and we went purposely 10:1 SCR and 8:1 DCR. Pretty much the same springs, Bilsteins (YOU absolutely NEED those!), 904 and the TC is 2200 RPM with a 3.55 rear. The engine and combo is really good for throttle steering out of any corner radius. With your cars extra 600#, more cubes would help but upping a 360 to 10:1 SCR will be a big + step.

And let me spend more of your money LOL. For that kind of driving, a 4 speed would be even better. Getting the engine braking diving into the corner helps set the weight up for better initial steering, better weight transfer on acceleration, and the instant torque to the wheels helps too.

But if you stick with an auto, I'd get the engine CR up and SCR up (via a steep ramp cam to get the least amount of advertised duration), and LOWER the TC stall speed. That last item is to minimize the 'mush' time you spend with the TC partially locked. Throttle steering an RWD car is all about a solid connection between from your brain, through your right foot, and to the torque applied to the rear wheels. Any mushiness in that 'linkage' makes it more uncertain in throttle steering and thus slower to drive.

(That, and the engine braking, are the 'why's' for manual trannies in road racing and rallying.... As a point of interest, the Dodge Challenger slap-stick mode puts the torque converter in a mode where it is partially locked so you get decent engine braking into corners and a super-quick lock up when the throttle is applied. In that way, they made it as close to a manual as you can with an auto....)
 
MOPAROFFICIAL said:
Just weigh the big and small end of the rod, because you need to match those weights with the new one by grinding some off each end.maybe.
Click to expand...
The 'maybe' is the operative word LOL.... For a simple rebuild, I personally would not be concerned. No big cams or high revs here.

JoePole1 said:
Just found a good piston/pin assembly for a 1996 (mine is 2001) on ebay. If the crank and bore is good i can match weight of used piston assembly to my bent and swap on my rings.
Click to expand...
New rings, right?
 
I can give you some awesome roads to drive when you get down this way again. Look at US250 west of Staunton VA over to the Elkins WV area. Make sure your brakes are 100%!).

I know 250 very well. I ride a motorcycle and just about any road West of I81 into WVA is a blast.
The engine and combo is really good for throttle steering out of any corner radius.

When I say spirited driving, I am not talking about road race extreme. I like fun roads and my current combo is pretty satisfying. Not a racer. Besides, I wouldn't want to break anything especially far from home.

And let me spend more of your money LOL. For that kind of driving, a 4 speed would be even better. Getting the engine braking diving into the corner helps set the weight up for better initial steering, better weight transfer on acceleration, and the instant torque to the wheels helps too.

Would love to but can't cover up $3500 for this conversion. Too close to retirement and the wife thinks the car is AOK as is.

But if you stick with an auto, I'd get the engine CR up and SCR up (via a steep ramp cam to get the least amount of advertised duration).

Please suggest.

I have converted to slap-stik and use it often but never heard of Dodge Challenger slap-stik mode. Was this exclusive to T/A AAR cars?

Was going to reuse rings due to low mileage on engine but I guess the bad rod throws that out the window.
 
JoePole1 said:
I have converted to slap-stik and use it often but never heard of Dodge Challenger slap-stik mode. Was this exclusive to T/A AAR cars?

Was going to reuse rings due to low mileage on engine but I guess the bad rod throws that out the window.
Click to expand...
Ooooops, I was not clear at all! I was speaking of the modern Challengers not the originals. (And they probably do not call it 'slap-stick' anymore.)

I personally would not even think of re-using the present rings. Maybe just me, but I never have, and they certainly will have some wear on them. I'd personally lightly re-hone and re-ring if the bores are good. BTW, I was thinking, why not take the block to the local shop (since it is stripped down) and ask them measure the bores and see how much wear and taper that you have? Then you will know if it is suitable for stroking as-is..... you might get lucky.

Understood on the trans cost.....you just need to deliver pizzas for a year after retirement to get the money LOL. But think about those Bilstein shocks if you don't already have them. And glad you know the roads down here.... sounds like your motorcyclin' has gotten you familiar with a lot of areas.
 
Ok. So I installed the piston assemblies (minus bent #8) with #5 in the 8 hole and checked TDC sequencing. All good. I also crudely measured piston deck height with feeler guages. They were down in the hole roughly .050. That along with visible cylinder cross hatching, no unusual rod bearing or journal wear and no piston skirt damage, I am going to call it good. The final inspection will be the crank bearings when I replace them. Have I missed anything? Comments?
 
Ok? Good to know when I choose a cam I guess. The important thing is they are all roughly the same and pretty sure that's what they were out of the factory. Plus I have a shot at my budget.
 
JoePole1 said:
This is going to be a budget street engine built for reliability with about 375 hp and 400 tq.
Click to expand...
To get to your power target is gonna take about a 235@050 cam right? Which being about a 288 roller, right? so say you get a 284/110 cam.
the Ica is gonna come to about 68*
Your Scr with 62cc heads is gonna come in at about 9.5
Static compression ratio of 9.5:1.
Effective stroke is 2.69 inches.
Your dynamic compression ratio is 7.39:1 .
Your dynamic cranking pressure is 146.31 PSI.
V/P (Volume to Pressure Index) is 119...................................... 119VP
You see that VP of 119?
VP is a performance indicator of how the engine will perform from stall to about 3000/3500
Since the VP is so low on this combo, I'm guessing you are planning on purchasing a Hi-Stall TC and some bigger rear gears. I hope so, cuz if not, in comparison a stock 5.2 Magnum makes about 137VP.

Here is your same engine, but with the Scr jumped up a bit
Static compression ratio of 10.4:1.
Effective stroke is 2.69 inches.
Your dynamic compression ratio is 8.06:1 .
Your dynamic cranking pressure is 164.08 PSI.
V/P (Volume to Pressure Index) is 133.............................. 133
You see that VP of 133? Still less than the factory 5.2 Magnum......
but an improvement of 133/119=Plus11.8%, for your combo, which is similar to going to a 3.55 rear gear from a 3.23; 3.55/3.23=Plus 9.9% TM

3500 with 3.23s and 26 inch tires, and a TF is about 33mph
The power of that 284 cam will peak at about 5600, so the torque peak will come in around 4100 rpm or 38 mph with 3.23s.

So now add up the cost of the hi-stall and bigger gears, versus a set of hi-compression pistons, installed.
And I would recommend floating the pins,at extra cost,so next time you can separate the rods out yourself
Next time?
There is always a next time, when the engine ain't stock no more.
Now here's the secret; the compression jump will allow you to run about one size smaller cam. So say a 276/110
Static compression ratio of 10.1:1.
Effective stroke is 2.77 inches.
Your dynamic compression ratio is 8.04:1 .
Your dynamic cranking pressure is 163.55 PSI.
V/P (Volume to Pressure Index) is 139................................ 139VP
See there you go, back to 5.2 Magnum status, and you can run the factory stall and gears, if you are so inclined. You could even run a 2bbl on that.
I have; on a 340LA with complete 318 top end, with it's factory 240/248/112 cam. How much power did that make? Well considering that it was now nothing more than a hi-compression big-bore teener, not much.
But ohhhhhh the torque! It was amazing.
The way I see it, right now you are about $600 to $700 away from having a dynomite short block; that's pistons and boring and a clean-up.
Or you can put it together as is, and spend the 600/700 on a good TC. Your call.
If you try this with the stock TC, whatever it stalled at before you took it apart, now with the 284 roller in it, it will stall at less......... because of the lost cylinder pressure.145psi@119VP is not good..163/139VP is excellent for an iron-headed, tight-Q, 360
Just trying to help.
Happy HotRodding
 
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I'd still have the crank checked....I agree on the 9.5 SCR. Sure a lot better than the 360 LA.

OP, did you like the way the throttle picked up before with that 2600 stall TC? Or was that the source of the /no torque' comment? Just trying to get a feel for what sized cam might seem right for you.... Is it correct to assume you are wanting to get a good improvement up in low-mid RPM torque?
 
Trying to digest all this information. Not disputing it.

Oddly enough my current smog head, flat top .030 LA360 has a measured cranking pressure of 170-175 across all 8.

I am estimating that pistons,rings, Pin install, bore would be about $1000 for the Magnum in my neck of the woods.
Plus I will need to magnaflux my crank. $?????
Still need intake, cam, carb, linkage, gaskets, LA front, Hardware....
That is another $1200 or so added to the $600 already invested.

I installed the TC along with my current LA combo so I cannot compare it. The Satty had a worn out LA318 2bbl with stock TC prior.

Correct. My goal is low-mid RPM torque and I currently run 2.71 gears. Purchased 3.55's to go in along with the build but would consider steeper for the A518 trans which would be next in line for mods. Not sure when that will happen.

I know I have some variables with the trans and gear. Sorry.
To me, budget is a major priority. That being said I am positive I can have a really fun ride within my goal.
A perfectly matched combo....No. There is always room for improvement.

Thanks for your input guys!!
 
JoePole1 said:
Oddly enough my current smog head, flat top .030 LA360 has a measured cranking pressure of 170-175 across all 8.
Click to expand...
Does not compute..... If that is true, the the pistons are in no way stock, or the cam or cam timing is really hosed, or your gauge is broken. From the factory, it should be around 120-130....

So if you really have 170-175 on that LA360, then your SCR it up in the mid 10's and your cam is not very large. A Magnum with lower SCR is gonna be a dissappointment for low-mid RPM torque by comparison.

If your LA360 supposedly had stock .030" pistons, then I'd suggest trying a new compression gauge 1st.
 
I got that too.
That much pressure with iron smogs would rattle the pistons to death on pumpgas.

Really your 2.71s are killing your performance.
OK, the following examples are pulled out of a hat and may bear zero resemblance to your engine.... but the relativity remains relatively accurate,lol.
Say your engine makes 200ftlbs at stall, and you have a regular TF with a 2.45 low gear, and for ease of calculation, you have 24" tires.
Your take-off torque before TC-TM will be;
200x2.45x2.71 =1328stockftlbs to the road.
Which is not enough to spin two normal sized tires
Say you did nothing to your compression but added a big cam, so that your cylinder pressure dropped, and your engine now makes only 180 ftlbs at stall. Now she will be putting down just
180x2.45x2.71=1195 very sick ftlbs.The suckiest performance ever. With 2.71s and a stock TC nothing is gonna happen until ~35mph
But say you did nothing to your engine at all, but instead installed 3.91s.Now your take-off torque will be
200x2.45x3.91=1916 looking goodftlbs, just enough to bust 'em loose wind her up and smoke 'em.
But say you put a 2800TC in there with 3.55, and now your engine is winding up to 260ftlbs. Now your take off torque will be
260x2.45x3.55=2261 screamingftlbs... still with the untouched engine. Now you have enough torque to put a bit of a cam into her, at the stock compression ratio, and have enough left over to smoke the tires.
Say the new cam dropped 20 ftlbs, so you are down to 240, then
240x2.45x3.55=2087looking good again ftlbs, still enough to light 'em up, and now, if she can carry the torque to when the power hits, you got a screamer. And that is where the cylinder pressure comes in. If the engine runs out of steam before the power hit,the tires stop spinning,the nose drops, and you the pilot says WTH. Then you battle up to the torque peak at say 3800/4000 and then she settles in on the long haul. Cylinder pressure will get you thru that stinking lull.
But honestly for a streeter, it's all in the TM; even a slanty can be a lotta fun with enough TM. As can be seen in the examples above, your first go-to is the TC, followed hottly by the rear gear. There is NOTHING you can do to your street- engine,short of supercharging it, that can compare to TC-plus-gears,nothing.
But say you did pump up the compression, and dropped one cam size; now the pressure might be back at 260 and you can drop a rear gear to 3.23s. Now your take-off looks like
260x2.45x3.23=2057, still great looking ftlbs, and now you can cruise the hiways at 65=2700 or less.
In my experience, I only need about 1600 ftlbs to spin the biggest BFG streets. In the above examples I aimed for 2000ftlbs, to allow for a margin of tuning errors, and the possibility that you might want to install a traction aid and actually convert that torque into something other than annihilating the tires, unlike me,lol.
 
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Ok. So the factory Magnum 9.0:1 (thin head gasket) ain't getting it done. Let's say I spring for new slugs. These are going to occupy more real estate up top. Right?
Won't that create issues with valve to piston clearance as well as valvetrain/spring geometry? Shorter pushrods, different valvespring, keepers......$$$$$$$$$$$$$$$$
 
That's a lotta questions some are yes-answers and most are no
I wanna talk about the current 360LA
Lemmee see if I got this right; it's 30 over with smog heads and a Crane HV-260-2, a 904/2600and 2.71s at 3600pounds, with a 600Eddie.
Assumptions
When I do the math on your engine, and a thin headgasket, the absolute highest Scr I can get is 8.5. If I assume that Crane is advertised at 260intake duration, and assume it is in at 106*, and then the really big deal, assume you are at 210 ft elevation;
then the absolute best pressure I can squeeze out of the calculator is 8.5Scr/143psi@130VP
now 130VP is normally a pretty good number....... for a 318,lol. So I get why you would say "no torque". The 2600TC should help your engine get to where the torque is...... but the 2.71s just cripples it, and the 3600pounds are not helping.
You know the problem is a total combo problem, but principally the cylinder pressure and rear gears
At 2600rpm your LA smogger could be putting out 300ft lbs, at the rear wheels this could be
300 x2.45x2.71=1992ftlbs. This should be plenty enough to spin two tires. That is to say lots of torque.
If you cannot spin both rear tires, with the current combo,,then I suspect either I have made some incorrect assumptions above, or your tune is off, or you have a cylinder sealing issue, or the TC ain't a 2600.
But lets continue;
With your proposed move to 3.55s, and using the above numbers; 300x2.45x3.55=2610 ftlbs, this is smokin' hot, spin all the way thru first gear, torque.
Ok now lets see what happens when we increase the compression in this combo.About the highest you can run is 9.3Scr/for 160psi@145VP This is an improvement in VP of 145/130= plus 11.5% Now granted your 2600 is gonna boogie past the fattest part of this improvement, but you cant argue with the pressure boost of 160/143=11.9%. At peak power, this represents about 4% power increase, but at 2600 it could be 8% torque increase, I'm kindof guessing here. So then 300 x1.08=324ftlbs and
324x2.45x3.55=2818 ftlbs now. But how about with the 2.71s,you ask?
324x2.45x2.71=2151ftlbs

The point I'm trying to make here is that TM is gonna make or break your 360LA combo, and since you already have a 2600TC.... NOW... is the time for gears, because this is the next biggest bang for your buck. For a streeter,with a hi-stall, absolutely nothing else you do to your engine short of supercharging it, is gonna compare . 3.55/2.71= a 31% improvement in TM. This would be like increasing your torque everywhere in the rpm band by that same amount... and normally-aspirated, that is just not feasible.
So now lets talk about gears
There are three (at least) criteria for choosing a reargear; 1) power at take-off,and 2)power at a particular rpm, and 3)power at whatever trap you choose. And it is not always that one gear will do all three. So far we have been talking about getting to the power at take-off.
Now lets talk about power at a particular rpm. Lets choose 32 mph, cuz that's where I like to blast off from.
Lets say that HV260 cam makes peak power at 5000, peak torque at 3500, and likes to be shifted at 5500. So you are gonna want to be between 3500 and 5000, preferably at the bottom so you got somewhere to go,lol. Ok,So; I come up with 3.55s to get you 3780@32mph, and you are gonna have to shift at 47mph. But I like 3.23s better, to get you 32@3440, and upshift at 51mph. So in this case I would choose 3.23s
Now going back to the take-off, these 3.23s would make 300x2.45x3.23=2374 ftlbs on the start line, more than enough, because you have that 2600 working for you.
Now if it's not fast enough for you from 32 to 51, you can A) choose more rear-gear,B) make more torque, C) supercharge it, or D) get a bigger engine, or E) make the car lighter.
as to A), more gear; you're gonna lose time in the shift, and it will mess with your other targets.
as to B), The only way to do this is more cylinder pressure
as to C) D) and E), these are self explanatory.
And finally
If you cannot spin both rear tires, with the current combo,,then I suspect either I have made some incorrect assumptions above, or your tune is off, or you have a cylinder sealing issue, or the TC ain't a 2600.
 
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I don't know if you have fixed your problem yet but I believe Chrysler sales a rod piston ring and bearing assembly might save you a little bit of money believe it or not to go to the dealer there is a letter indication on the bottom of the block to tells you which piston you need at Via ABC or D I hope this helps you
 
JoePole1 said:
Won't that create issues with valve to piston clearance as well as valvetrain/spring geometry?
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Good question: That is why there are deep valve reliefs in those types of pistons. Checking piston-to-valve clearance in a 10:1 SCR 340 with KB flat tops at .000" deck clearance, there was something like .120-.150" clearance with a 268 duration cam in at 107 degrees ICL and 1.6 rockers with valve lift at around .490"/510". It was so much clearance that I did not bother to measure it closely.
 
Thanks Tbone. I located one on eBay as well.

I went to Mopars at the Valley today and ran into the Tech editor of one of the major Mopar
magazines. He said that he would not trust the block of crank. I don't want to doubt his expertise but man this engine sure looks solid. I guess the previous owner could have been BSing me and yanked it before it let loose. It's almost completely apart so I guess a magnaflux of the crank and block would answer that. Correct?

AJ....good info on my LA360
Your assumptions are pretty good. Not sure about the 106* cam install. I believe it was straight up.
I am also not sure about the piston to deck height. I bought this motor rebuilt and have about 8000 miles on it. I tore it down when I got it but did not pay much attention to the pistons. They are definitely..030 and flat tops with no valve relief.
I also forgot to mention that i milled my heads .030. With that said 8.5 is what I estimated as well. Also my converter is actually 2500 and the tires barely spin.

I was really hoping to take advantage of the Magnum's rollers and 1.6 rockers.
Another option is to keep my La360 and use the EQs with the closed chambers upping my CR a bit and add cam but that's about the same scenario I have now.
 
A lot of cams, maybe most, IDK, have 4 degrees advance built in at dot to dot., making a 110 cam go in at 106 ......theoretically.
For typical street use;
Flat tappet cams designed for the 904 lifter, have some of the fastest acceleration ramps around, so I wouldn't lose any sleep over not having a roller. And the 1.6 arms by themselves , are also not a big loss. These are minor blips in the big picture that are easily overcome at your power level, just by selecting the right cam. Your crane is already set up to be a torque monster. Here's the rub, If you put a bigger cam in there, as it now stands, your bottom end will get worse. Not might get, but will get. So you need to get to the bottom of why it is so gutless now, and if something is wrong,fix it!
So, the first thing I would do is check that the carb is fully opening with the pedal floored.
Next is to check that cam, for lobes going flat. If the cam is good, then next is a Leakdown test, and after that is a compression test with a known good gauge.
If those give favorable results, I would dig into the ignition-timing, first proving TRUE TDC.
I suspect you are gonna find some issues with these tests... but if not...............
Get some gears in the back, ASAP, and then after you wipe the silly grin off your face..... then you can revisit that stinking convertor.
In post #26 I think I read 2600TC; was that a typo?
A 100rpm is not a big deal, but I gotta wonder if it's working right?

But I'm still going on the assumption that your Crane HV260-2 is a 260 advertised duration cam; I could not find specs on the web.

Here's something to brighten up your day;
A long time ago I had a 270/110 Hughes cam in my 360 with a manual trans, and a starter gear of 9.44.. That hummer would boil the hides right off idle. In fact one of my favorite things to do was,with the line-loc on, break the 295s loose and then idle the engine down to just barely be spinning them; then listen to the tires howl and shriek as they warmed up and began to drag the rpm down...... to which I would respond with just a lil more gaspedal. Fun times.
That 270* is about 1.5 sizes bigger than your 260*, and at 8.5 compression ratio, it would have been awfully soft on the bottom there. So I pumped the chitoutof the compression ratio.
Now consider what 3.55s would do for you in comparison;3.55x2.45=8.70.Looks a lil soft..... until you factor in the TM in the TORQUE convertor, which is supposed to multiply engine torque, when the vehicle is standing still; that is what they do. I have read numbers as high as doubling the engine torque with the vehicle at rest. As the car moves out, the multiplication diminishes but at WOT, it rarely falls below 10 or 5 % multiplication.
Now lets look at this in your car. At rest the TC should double your TM to 8.7x2.0= 17.4! Yikes! But as the car moves out, lets say it falls to plus 8% by 3000rpm/24mph, with an effective ratio now of 8.7x1.08=9.40;
does that number look familiar? Why yes AJ isn't that what you were running in your torque-monster? Why yes Joe, that is correct.
That is what TCs are supposed to do. :)
And here's a lil something to dim the light just a lil.
I suspect your TC ain't doing that :(
Why do I think that? Well, 2.71x2.45x2.0=a tire shredding 13.27 effective ratio; which should bust the tires loose instantly with the torque that is theoretically available at minimum 2500. As soon as the tires spin,the TC backs off, so you gotta have engine-torque to maintain the spin. And at a minimum 2500rpm now, there should be plenty of power to do whatever you want.
I could tell you to pull that TC outta there right now....... BUT;
but for all I know,your engine could be down on power for multiple reasons, and we need to get to the bottom of that first........ cuz if you spend a quarter of your budget on a new TC and nothing changes; you're not gonna like me very much. And I am not well-off enough to pay for that mistake.And I know of no good way to test the TC in-chassis with an unknown engine.
But like I said, your HV260-2 is an unknown to me. If for instance that 260 number had nothing to do with duration,and that cam was really a 292/292/108, then I would tell you exactly what is wrong with your combo.
No laughing matter,lol
 
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JoePole1 said:
He said that he would not trust the block of crank. I don't want to doubt his expertise but man this engine sure looks solid. I guess the previous owner could have been BSing me and yanked it before it let loose. It's almost completely apart so I guess a magnaflux of the crank and block would answer that. Correct?

AJ....good info on my LA360
Your assumptions are pretty good. Not sure about the 106* cam install. I believe it was straight up.
I am also not sure about the piston to deck height. I bought this motor rebuilt and have about 8000 miles on it. I tore it down when I got it but did not pay much attention to the pistons. They are definitely..030 and flat tops with no valve relief.
I also forgot to mention that i milled my heads .030. With that said 8.5 is what I estimated as well. Also my converter is actually 2500 and the tires barely spin.

I was really hoping to take advantage of the Magnum's rollers and 1.6 rockers.
Another option is to keep my La360 and use the EQs with the closed chambers upping my CR a bit and add cam but that's about the same scenario I have now.
Click to expand...
As for the block, I did not think of that. It is possible that a hairline crack could have been formed if the rod was bent due to coolant getting into the cylinder and the cylinder hydro-locking...seen it before. A pressure test of the block is an alternative way to find that... And magnafluxing the crank is not what I would do.... check it for straightness and indexing first. If it is off, then replacing may be the easiest route... again, consult with your shop on that.

OK on the present LA360. With the flat top pistons and no eyebrows, I suspect they are about .100-.110" in the hole and are stock replacements. With the heads milled .030" and that piston and stock Felpro heads gaskets, then the SCR is around 8.3 so are about right. No way that the cranking pressures will be 170 psi unless the cam is all hosed up and waaaaay advanced, like 2 or 3 teeth (40-45 degrees)! And the lack of tire spin attests to that.... though the rear gear is not helping, the TC should compensate some for that tall gear if you had a true high compression engine.

Possible changes in order of increasing SCR:
  • Putting the EQ heads and thin .028" head gaskets on the LA360 will get the SCR up to 9.1. Better than 8.3 by quite a bit, but not quite maximal torque territory. With that tall rear gear, IMHO you need all the help you can get.
  • The LA 360 with H405CP pistons is 9.2 SCR; no better than what you have with just slapping the EQ heads on the present LA360, but lower than the Magnum setup below.
  • The Magnum block is .015" shorter, and the stock pistons taller, so that gets you up to 9.4 SCR with stock Magnum pistons and deck, the EQ heads, and the .028" thick head gasket.
  • Next step up is the LA360 with H116CP pistons (no re-balance should be needed with those), and EQ heads. That gets you up to 10.2 SCR with that thin head gasket, and 9.95 with a .039" head gasket. Since your LA bores are still fairly fresh, maybe you could do this with just a hone in the cylinders, with new pistons and rings. This looks to be the cheapest way to go to get around 10:1 SCR. Maybe $650-700 for new pistons & rings, shop work to put them on your rods, and a fresh gasket set.... plus all your time.
  • Finally, the Magnum with KB107's.... which are actually relatively cheap right now at $270 per set of 8. SCR is 10.35 with .051" thick head gaskets (standard Felpro's), and 10.7 with .039" thick head gaskets. Getting a tad high IMHO for the last one, but can be fixed. AND you get some quench effect to help fight detonation. You need to think hard about that high SCR.....it is getting into the range of serious tuning needed. Annnd, the piston + pin weight is higher than the stock Magnum by around 30 grams.... too much difference to not re-balance. So THEN you would need to:
    • Add weight to the crank.... maybe another $250-350??
    • Or, take weight off the pins and pistons.... possible (You need to be a bit careful to do this.)
    • Or, put in SCAT I-beam rods and then take weight off the crank..... $300 for the rods, but relatively inexpensive to do the crank since the rods and pistons are well balanced from their factories and so don't need to be touched
    • This last sub-option of new rods, rings, pistons, and crank-only balance is around $800 added cost above the straight Magnum with no changes IMHO.... all else being equal, and if your Magnum crank and block are good, etc.
While I would not kill for 1.6 rockers, they are an advantage. I became a believer with a 351 Cleveland; the stock 1.73 ratio made it sooo easy to get good lift with small duration. Better for low RPM torque. My son and I went with 1.6 shaft rockers on his 340 for that reason.
 
next chapter would be to just do a stroker if the crank needed grinding or almost for the cost of the balance job
thanks for the calks Aj at least one can make an informed decision not gossip or guess work- opinions from those who have done similar builds really helps
#300 for rods rebuilding stock rods costs almost that unless you are like me and can DIY (my time's free - right?)
agree with Aj on the rockers-- were these roller rockers Aj? what did your sweep pattern turn out to be?
 
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