Waking Up a Turd

Hello All,
Im a noob to this forum, but have been lurking for a while. Im general impressed with the vast amount of knowledge around with the LA engines. Im hoping you all can point me in the right direction with my turd of a 360.

A long time ago i acquired someone else's project, that they lost interest in. Its a 84 D150 shortbox.
I know, I know, 2 strikes already, A noob, AND a truck! Please hear me out!!!!!! It will get better, i promise.

This truck was built with a 318, 904, and 8 1/4 combo, and was on propane! yuk!
It now has a 360, with a 727, and an 8 3/4. Its warmed up nicely, But the package is still slow. I was hoping to get pointed in the correct direction by some small block experts.
My main focus, is that this whole package is slower than the 79 Little Red Express Truck 1/4 mile specs, that Alpar lists on their site "15.71 seconds @ 88 MPH" I made it to the local strip, on a Friday Street Legal Fun Night, and wound up with a consistent 16.4

As stated, I picked up someone elses project, And thus im not too sure exactly whats in it. This i do know. The engine is a 79 casting, The heads are 915 J heads. It has an Offenhouser Dual Port intake (340 square bore version). Topped with an Edelbrock 650 carb.
The previous owner said it was built with "10-1 flat tops" and "the second biggest Mopar Purple shaft cam"
My digging into cam specs would let me think the cam is the specs listed below.

PRODUCT DESCRIPTION

Fits: Small Block, Advertised Duration 284/284, Lift .484/.484

Camshaft, Hydraulic Flat Tappet, Advertised Duration 284/284, Lift .484/.484, Chrysler, 273, 318, 340, 360

Cam Style: Hydraulic flat tappet

Basic Operating RPM Range: 2,600-6,000

Intake Duration at 050 inch Lift: 241

Exhaust Duration at 050 inch Lift: 241

Duration at 050 inch Lift: 241 int./241 exh.

Advertised Intake Duration: 284

Advertised Exhaust Duration: 284

Advertised Duration: 284 int./284 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.484 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.484 in.

Valve Lift with Factory Rocker Arm Ratio: 0.484 int./0.484 exh.

Lobe Separation (degrees): 108


I use this truck as a summer driver, and will occasional take it to the strip. This winter, i think i will pull out the engine, and check it over. I want to ensure that the bottom end is sound, and make some changes as required to make it faster than a little red truck.
I know that the intake manifold is mismatched to the cam, and plan on replacing it.

With those details out of the way, i can ask some questions:
What would the recommended cylinder head be for this type of combo? If you subscribe to the Engine Masters basic recommendations, "Buy the best head you can afford" motto, I am wondering if i would be better off with trying to source a later swirl port head, and having them rebuilt (likely about $1000 or more with 2.02 valves) or going with a Indy LA-X or Edelbrock performer head? Machine work is very expensive in my area. The cost of machining would narrow the difference down substantially, making the LA-X head quite interesting to me. Actually more specifically im interested in the INDY/IMM SB Mopar Heads.

Since this will be a mostly street driven unit, At what point does the larger port volume start to affect drive-ability?
Is this camshaft even big enough to fully make use of an aftermarket head? or would i be better off to try to port the old J heads myself?

What kind of cranking pressure should i have if this engine truly had 10-1 compression?

And finally Intakes...... Is the edelbrrock performer or performer RPM a better choice for this heaver vehicle? Is there a vintage made dual plane manifold that would be a good choice? I have really begun to dig the older "Just stepped out of the 90's" look of this truck. and for that reason, i thought i would try keep the offy intake, but it is a hindrance.
Im going to put up another post in drive trains to help me identify, and choose a proper stall converter for this unit

Looks great. Nice truck and welcome to FABO. What rear gear do you have in your 8 3/4? May'be I missed it in your description.

Its a 3.23 gear. And i put in a Detroit True Trac.

Hooks up nicely now, street tires. p275
I had to leave it in drive at the track, as i was having a shifter cable issue, The PO installed a B+M ratchet shifter, and the cable was melting.
It would shift at 4900- 5000. Chirping the tires at the 1-2 shift
I would like to have a set of 3.55 or deeper, But don't think i will do that mod unless i find a A518 for it.

Mile Maker said:

Its a 3.23 gear. And i put in a Detroit True Trac.

Hooks up nicely now, street tires. p275
I had to leave it in drive at the track, as i was having a shifter cable issue, The PO installed a B+M ratchet shifter, and the cable was melting.
It would shift at 4900- 5000. Chirping the tires at the 1-2 shift
I would like to have a set of 3.55 or deeper, But don't think i will do that mod unless i find a A518 for it.

Click to expand...

Ya, with 275's you final ratio is equal to a 2:87 or something like that. There is a formula to figure it out. Do you go cross the finish line in second? How many rpm? 3:73 or 3:91 would be a better choice.

Mile Maker said:

What kind of cranking pressure should i have if this engine truly had 10-1 compression?

Click to expand...

There's the rub.
@Mile Maker
Where exactly are you in Alberta or at what elevation?

With a 284/284/108 in at +4, you'd be looking at an Ica of 66*
At 2250 ft, with a TRUE 10/1 Scr, and an Ica of 66*, you'd be hoping for 148psi.
If you truly had 148psi, your bottom-end take-off would feel like a 318Magnum to about 3000 rpm, which with 275/60-15s and 3.23s is about 30mph. 5000 in first is about 48 mph, and second will get you ~80
That cam is barely waking up at 5000. It might powerpeak at 5400, and the 1-2 shift might want to be at 6000.Second should pull to 92@5700. If you stick it in third you'll probly lose ET.

At this point, shifting at 5000, you could probably go faster with a cam two sizes smaller. You need to rev that thing!

AJ/FormS said:

There's the rub.

Click to expand...

Hey AJ, I was just trying to call you to this thread. Thanks for stopping by.

AJ typically steers the form in the right direction

It honestly sounds like it's over cammed and under geared right now. If you have J heads, you might port them or leave them for now and get a bit smaller camshaft. Might be able to trade the 3.23 stump for something in the 3.55-3.73 range.

Im In Medicine Hat AB. 2260 Feet.
This engine was built more than 25 yrs ago, And also sat for 20. I suspect there was some rust on the cylinder walls.
As i was first driving this truck, and doing some tuning, There was more blowby than i wanted to see. I did a compression test at that time.
I averaged 130PSI. with 2 cylinders at 125, and one at 140.
Since this compression test, i think some of the blowby has cleaned up.
This winter i want to open it up, and at least put some new rings on it, with a fresh hone. Im also debating on some of the oiling system mods, as described in this forum. Drilling out the passages, and slotting the bearings. If nothing else it will make me feel good.

its been a couple of weeks since i raced, But i think it just shifted to 3RD at the finish line. I recognize that i might shave off some time with improving my launch, and shifting a bit higher.

Okay let's hear what you already have for an idea . it'll save some time

RammerJammer75 said:

It honestly sounds like it's over cammed and under geared right now. If you have J heads, you might port them or leave them for now and get a bit smaller camshaft. Might be able to trade the 3.23 stump for something in the 3.55-3.73 range.

Click to expand...

I agree to the over cam and under gear. Do you think the heads will support the cam, If i replace the intake?
I want to keep it street able, and hesitate to replace the gears until i have an OD trans.

MOPAROFFICIAL said:

Okay let's hear what you already have for an idea . it'll save some time

Click to expand...

First figure out exactly what kind of cam and pistons are there.
My Ideas are to replace the intake with one more suited to the cam. Edelbrock performer or RPM based on recommendations here.
Assuming they are 10-1 flat tops...... Freshen up the bottom end with new rings.
Check out the heads. If they are just stock J heads, i would seriously consider replacing them, as i believe rebuilding them + port work would be nearly the cost of replacement. Ether Indy heads, or Edelbrock. Based on recommendations from here

Mile Maker said:

First figure out exactly what kind of cam and pistons are there.
My Ideas are to replace the intake with one more suited to the cam. Edelbrock performer or RPM based on recommendations here.
Assuming they are 10-1 flat tops...... Freshen up the bottom end with new rings.
Check out the heads. If they are just stock J heads, i would seriously consider replacing them, as i believe rebuilding them + port work would be nearly the cost of replacement. Ether Indy heads, or Edelbrock. Based on recommendations from here

Click to expand...

Without more gear, the intake probably won't make much difference for you, if anything it will likely just move the curve even higher and be less or equal on the low end (under 4k).

Like AJ said: rev it.

If gears aren't on the list right now, then a converter is likely the next best step. A modern high-stall should still let you street drive it but will definitely help get your rev counts into the meatier part of your torque/hp curves. Rather than ask about converters, call up the custom converter suppliers and get recommendations. Having vehicle weight, gear, tire height and peak torque will be important for them to make an educated guess.

AJ/FormS said:

There's the rub.
@Mile Maker
Where exactly are you in Alberta or at what elevation?

With a 284/284/108 in at +4, you'd be looking at an Ica of 66*
At 2250 ft, with a TRUE 10/1 Scr, and an Ica of 66*, you'd be hoping for 148psi.
If you truly had 148psi, your bottom-end take-off would feel like a 318Magnum to about 3000 rpm, which with 275/60-15s and 3.23s is about 30mph. 5000 in first is about 48 mph, and second will get you ~80
That cam is barely waking up at 5000. It might powerpeak at 5400, and the 1-2 shift might want to be at 6000.Second should pull to 92@5700. If you stick it in third you'll probly lose ET.

At this point, shifting at 5000, you could probably go faster with a cam two sizes smaller. You need to rev that thing!

Click to expand...

I am working on replacing the shifter cable, so i can manually shift it again. The new one is on my bench.
I think the intake is so miss matched, that it really doesnt feel like its pulling hard anymore above 4300. also the 650 carb is likely hurting things as well. although i suspect with a regular dual plane intake things will balance out better. Currently with the dual port design , i had to ritchen up the secondary's a bunch.

Once i find out for sure what cam it is, Where is the line between en edelbrock performer vs RPM? I know its a purple shaft, as i had the intake off to fix a vacuum leak before. Its a lumpy idle, And i can only pull 9-8" of vacuum at idle. I had to give it 18 Deg of timing to get that much vacuum.

Mile Maker said:

First figure out exactly what kind of cam and pistons are there.
My Ideas are to replace the intake with one more suited to the cam. Edelbrock performer or RPM based on recommendations here.
Assuming they are 10-1 flat tops...... Freshen up the bottom end with new rings.
Check out the heads. If they are just stock J heads, i would seriously consider replacing them, as i believe rebuilding them + port work would be nearly the cost of replacement. Ether Indy heads, or Edelbrock. Based on recommendations from here

Click to expand...

Get after it. You're all figured out.

Mile Maker said:

Im In Medicine Hat AB. 2260 Feet

Click to expand...

Ouch! yur in trouble; I'll redo the pressure calc for that, then I'll be back.

Mile Maker said:

averaged 130PSI. with 2 cylinders at 125, and one at 140.

Click to expand...

I love the Hat. Got a hi-school friend in Redvers.

You got thee problems, Two covered by @RammerJammer75
Namely 1)too much cam for the pressure ,or said another way; not enough pressure for the cam. And 2) not nearly enough gear for 82mph.

But I've already talked about the really big deal, not enough revs.
In the dragrace situation;
The lack of cylinder pressure mostly affects your performance below about 3500; and you can fix that with a hi-stall TC.
At the top of the track; the highest Mph will come with the engine in the powerband, and thru the traps, just as she has fallen off the cam. For 82 mph,and the 284 cam, that might be 3.55s for 82=5750@10% slip in Second gear. But hang on a sec;
If you shift that thing where it wants to be shifted, namely ~6000 on the 1-2 and trapping at ~5600, then that is gonna push the trapspeed up, and you might run outta gear with 3.55s, and be forced into Third. The engine rpm will fall into the basement, way off the cam, and then you are just driving to the finish-line. To trap properly, with that combo, in third gear, is gonna take a lotta lotta gear. For a streeter, waaaaay too much.
So, IMO,
If as you say, this is
For a Streeter;
then put drag-racing on the back-burner. Build your combo for street, and let the track be whatever.
Ok so with that in mind; Pay attention to your driving habits and style. Find out where your engine has the right amount of power for you NOW; as in what gear at what rpms. And where it sucks. Cuz the fixes are different, for different situations.
I am a streeter too. And I can tell you right off, that your pressure sucks,lol.
I weight about the same or maybe a lil lighter at 3650 me in it. My car spins any size street tire I can get into the rear tubs, to well over the speed limit anywhere in Alberta.
It has a 360/A833/3.55s/ a 276/286/110 cam. ...... and 180psi (alloy heads).
You have more cam, more stall, and more TM(Torque- Multiplication), and more Effective TM to the road.
What you don't have is pressure and rpm. And I don't recall seeing Headers and free-flowing duals.
With iron heads, you want the pressure to be as high as possible, until it hits the detonation wall, and that, with open chambers is gonna be about 160psi, for 91 or better gas. Subtract 5psi per grade of gas. If you want to run 87 gas at WOT with full timing, you will want to run 150psi or so. Add 5 psi or so for a tight-Q design, which you don't have. Ok so , with iron heads
160psi will be very strong.
150 will be adequate
140 will be typical , ho-hum
130 is already sucking
120 is totally feeble

Your Static Compression ratio, AND your cams ICA, or Intake closing Angle, TOGETHER, determine how much cranking pressure your engine will make. The bigger your cam is, the higher your Scr will need to be, to make the target pressure.
Since you plan on tearing the engine apart this winter, that will be the time to fix this.

Moving on, I feel, for a streeter at 2250 ft elevation, that 284/484/108 is a tad too much. Yes at 4400 or more rpm, it's a lotta fun, but it sacrifices everything below 3000 to get it. And yes, you can put a 3000TC in the trans to eliminate that. But unless you pay the big bucks for one, it ain't going to help your already terrible fuel economy. Besides 4400 in first gear is about 40 mph. So unless your tires spin, that's a long time to wait, to get to where the power starts. Yeah/no, that ain't my cup of tea. When I hit the gas, I expect to strike terror in the hearts and minds of all that hear it. I expect thunder, lightning, and excessive wailing of tires, with accompanying tiresmoke. Ok so maybe a bit of exaggeration there.
You can do all that with your truck right now, with 4.30s and a 3000/3500TC.Even with your 130average psi pressure. But how many miles a week can you afford to drive a thing like that.
For a streeter, absolute power is IMO not the Holy Grail. having the right amoun of power in second gear is. Once you get the pressure up a lil, first gear is gonna do a lotta spinning. So second gear is gonna be the gear you are gonna mostly be in. With 3.23s, you are looking at
30=1700,40=2250, 50=2810; Waitaminute; you see a problem here?Yeah/no; your 360 is not a diesel. Ok so Second gear is NEVER gonna work for anything but cruising with those 3.23s. And no other 3-series gear is gonna make it much better.
So that puts us into first gear. Still with 3.23s and with 10% slip, then;
24= 2500, 30=3130, 36=3810, 42=4400, 48=5070, 54=5710
So riddle me this; where does your 4400 to 5700 cam fit into this?
That's right; from 42 to 54 mph.
You can use a Hi-stall to get you to 30 in a hurry, but from there to 42,it's all on the engine.
So tell me, how often are you gonna be between 30 and 42 mph?
I'll guess at least as often as from zero to 30, and together those two might be ...... say 95% of the time, jus guessing. So, would it not be in your best interest to build your combo to have power in the area that you actually drive, than to optimize it for an engine speed that you will rarely see on your tach.
In Second gear with 3.23s@10% slip;
60=3700, 70=4330, 80=4950. Do you see 5700 there anywhere? Hey; I'm not being a smartazz.
The fact is that if the tires don't spin, you got a long wait to 42mph, then you got a quick scoot to 54mph, than yur dead in the water, until 70 mph, when the cam starts waking up again.
And if the tires do spin, spinning ain't winning. But it sure is a lotta fun.
So , if this making sense, then what's the cure?
This right here is a great start;

RammerJammer75 said:

It honestly sounds like it's over cammed and under geared right now. If you have J heads, you might port them or leave them for now and get a bit smaller camshaft. Might be able to trade the 3.23 stump for something in the 3.55-3.73 range.

Click to expand...

You gotta get the power down to where it is readily available, even it sacrifices dome absolute power, to get more power at lower rpms... which is where you are gonna be most of the time.And then make the reduced power zones shorter, with a bigger rear gear. The Gear chosen, will partly determine the cam. And the cylinder pressure will lock it in.
So without an overdrive, you might have to sacrifice hi-speed touring, to tighten up the rpms.
Lets try my favorite city gears of 4.30s.
Currently, your first gear road gear is 2.45x3.23=7.91.
With 4.30s it would be 2.45x4.30=10.54
That is 10.54/7.91= PLUS 33%. So your engine, by comparison, is gonna feel 33% bigger, torquewise ....... ANY TIME/ALL THE TIME. But right now, under 3000, she is feeling like a 5.2M,sooooooo now first gear is gonna be feeling more like it outta.
Lets look at the new First-gear(still 10% slip) rpms;
24=3340, 30=4170, 36=5000 42=5840, and in Second
42=3460, 48=3950, 54=4440, 60=4940, 66=5430, 72=5930
Look at the blue numbers; this is now where your 284* cam is on the pipe.
So as you can see, below 30, she is still struggling. Now you have a choice; Either keep the 284 and get a hi-stall. or keep the current stall, and bring the power down .
Le try a cam two sizes smaller; say 270/276/110 ( this is what I have). This cam peaks at about 5000, starts at 3500, and pulls forever with Edelbrock heads. Ok say 5500 with good heads. And again with the speeds;
24=3340, 30=4170, 36=5000 42=5840, and in Second
42=3460, 48=3950, 54=4440, 60=4940, 66=5430, 72=5930
Ok now we have it covered from 24 to 66 mph. The factory 2400 while not terrific, remember we now have a starter gear of 10.54 so it's only gonna be down there for a few micro-seconds.
Ok but, from 284 to 270 is two cam sizes; isn't that a big power loss?
If you are looking at just the engine, then Absolutely yes it is. But about half of what we lost on the top, is now on the bottom where we really needed it.And we multiplied that by plus 33% with the 4.30 gears! So if you convert the horsepower, back to torque, you will find that you now have waaaaaaaaay more average torque from stall to shift rpm, than you previously had.
But, here is a bonus,by slipping in the smaller cam your Ica is gonna come down, about half the difference or 14/2=7*. And that is gonna pump your pressure up about 10 psi... So now, your average is 130+10=140; what did I say that was? IIRC I said "adequate". So with no other changes than the cam/kit, you have transformed your slug into a tire frying slingshot.
And another nonus is that your 82mph trapspeed might climb to 86 and now in third gear at 4900 just about right on the power peak of that 270* cam!

So what did we spend?
a cam/kit
a 4.30 gear
lessee what else?
OkNope, that's all I got. lol.
Well, you are gonna have tirespin problems; so that's gonna cost some money to deal with.But you would have had the same problem with a hi-stall, so in my thinking, I won't count it,lol.
That leaves it up to you, if you want to chase a lil more pressure.
I would, but I turned into a pressure freak the first time I nailed it.

And finally; I said all that to bring you here.
You don't need the 4.30s and you don't need the 270* cam. I used those to introduce you to a different way of thinking,namely; putting the power where you need it, and saying to heck with absolute power.
What I would do; first, my 270 cam was about 223@.050. This is a terrific fun street cam. In your case, I would get a same 223@.050 but in a solid lifter cam. This will bring your pressure up another 5 or so psi, so now 145, dangerously close to being the max for 87E10 with open chamber heads.But the thing is, the 270 Hydro doesn't actually close the intake anywhere near the advertised number, it could be 10 to 15* later, which kills the low rpm pressure, beyond what the Wallace Calculator can estimate for. Whereas with a solid, you tell the intake exactly when to close. And that might get you a few more psi, say 148 now. And then some new rings might get you into the 150s, I guess time will tell.
And with the pressure now cooking, you won't need the 4.30s so much. They are still the right gear to pull it all together, but, you could sacrifice some of it.

What you could do is grab an A999 with it's 2.74-1.54 1-2 split, allowing the 4.30s to become 3.84s for the same First road-gear, but that's gonna make a big difference at 60mph. But the A999 has a slightly wider 1-2 split, so, in compensation, I would order the solid lifter cam on a 112LSA. This will reduce your pressure some, maybe 2psi, so back to 148. No biggie. Because this solid lifter cam will make a stronger bottom end Ima thinking we can drop another size in rear gear, to say 3.55s. Or we can up the TC to 2800, and leave the 3.23s in there..... see how this works? always trading.......
So where are we now?
Solid lifter cam,kit,and adjustable valve gear
An A999 trans.
And,....... OkNope nothing else.
Don't care about the intake/any 4bbl, headers optional but recommended, for sure a big free-flowing dual exhaust to let that solid-lifter cam do it's job, Hi volume fuel pump for that long third gear pull,3/8 fuel-line optional, good coil/any ignition,
brakes. Hyup, yur gonna need brakes. and big front tires, cuz the back ain't gonna be doing nothing except skidding when the front don't bite. And those pesky curbs keep sneaking around every corner, lol.
Ok so, now you get to think it over, and I get to go have supper,lol.
No editing on this post, if I typo'ed you'll have to figure it out,lol.

@mech1nxh
llort skniht em

The Offy dual port is a TERRIBLE intake.

I would like to see you put an air gap or performer rpm or an LD340 on it just to see what kind of improvement you would get. But yes, at least 3.73 gears, more compression. The Indy/IMM heads look like a sure winner, but if your rebuilding it, I would be leaning hard, as in planning as a definite, towards a 4 inch crank.

Mile Maker said:

Im In Medicine Hat AB. 2260 Feet.
This engine was built more than 25 yrs ago, And also sat for 20. I suspect there was some rust on the cylinder walls.
As i was first driving this truck, and doing some tuning, There was more blowby than i wanted to see. I did a compression test at that time.
I averaged 130PSI. with 2 cylinders at 125, and one at 140.
Since this compression test, i think some of the blowby has cleaned up.
This winter i want to open it up, and at least put some new rings on it, with a fresh hone. Im also debating on some of the oiling system mods, as described in this forum. Drilling out the passages, and slotting the bearings. If nothing else it will make me feel good.

its been a couple of weeks since i raced, But i think it just shifted to 3RD at the finish line. I recognize that i might shave off some time with improving my launch, and shifting a bit higher.

View attachment 1715596440

Click to expand...

thats not 10/1 cr. my 10.1/1 crank pressure is 182psi

so called 10/1 pistons are only half the equation without the head chamber cc's and gasket thickness. go Edelbrock and never look back.. IMO..

LJ67barracuda340 said:

so called 10/1 pistons are only half the equation without the head chamber cc's and gasket thickness. go Edelbrock and never look back.. IMO..

Click to expand...

Crankings only half the equation when you don't know what the cam is...

Wow. AJ. Thanks for braking that down.
I always knew the cam was mismatched, putting in the RPM at shift points sure adds another perspective.
Oh i do have 1 5/8 headers and dual 2 1/2" exhaust. It should be able to exhale OK.
I want to source an OD transmission, before i change gears. I want to be able to maintain some highway manners. Probably 3.73 or 3.91. I have to figure that all out yet. I have always leaned towards the 727, or the A518/ 46rh for the beef, But the A500 / 42RH seem to have the more desirable gear ratios. I will look into them more.

You have talked me into a different camshaft. I like the idea of a HYD roller cam, Mostly because of the engine oils available these days. I m just not sure if a retrofit would be worth the hassle.

Now about the heads..... The write ups i have seen suggest the J heads should have about a 70-72 CC chamber. How much effect on cranking pressure would be expected, if i chose a set of 65 cc heads?

Garrett Ellison said:

I would like to see you put an air gap or performer rpm or an LD340 on it just to see what kind of improvement you would get. But yes, at least 3.73 gears, more compression. The Indy/IMM heads look like a sure winner, but if your rebuilding it, I would be leaning hard, as in planning as a definite, towards a 4 inch crank.

Click to expand...

Stroking it is not yet in my plans.... I am still looking for a cheap solution.
I will be weighing all the costs as i go.
Ive also thought about a junkyard Magnum swap. If i find too many parts i cannot reuse, i will be weighing all my options.

Mile Maker said:

Hello All,
Im a noob to this forum, but have been lurking for a while. Im general impressed with the vast amount of knowledge around with the LA engines. Im hoping you all can point me in the right direction with my turd of a 360.

A long time ago i acquired someone else's project, that they lost interest in. Its a 84 D150 shortbox.
I know, I know, 2 strikes already, A noob, AND a truck! Please hear me out!!!!!! It will get better, i promise.

This truck was built with a 318, 904, and 8 1/4 combo, and was on propane! yuk!
It now has a 360, with a 727, and an 8 3/4. Its warmed up nicely, But the package is still slow. I was hoping to get pointed in the correct direction by some small block experts.
My main focus, is that this whole package is slower than the 79 Little Red Express Truck 1/4 mile specs, that Alpar lists on their site "15.71 seconds @ 88 MPH" I made it to the local strip, on a Friday Street Legal Fun Night, and wound up with a consistent 16.4

As stated, I picked up someone elses project, And thus im not too sure exactly whats in it. This i do know. The engine is a 79 casting, The heads are 915 J heads. It has an Offenhouser Dual Port intake (340 square bore version). Topped with an Edelbrock 650 carb.
The previous owner said it was built with "10-1 flat tops" and "the second biggest Mopar Purple shaft cam"
My digging into cam specs would let me think the cam is the specs listed below.

PRODUCT DESCRIPTION

Fits: Small Block, Advertised Duration 284/284, Lift .484/.484

Camshaft, Hydraulic Flat Tappet, Advertised Duration 284/284, Lift .484/.484, Chrysler, 273, 318, 340, 360

Cam Style: Hydraulic flat tappet

Basic Operating RPM Range: 2,600-6,000

Intake Duration at 050 inch Lift: 241

Exhaust Duration at 050 inch Lift: 241

Duration at 050 inch Lift: 241 int./241 exh.

Advertised Intake Duration: 284

Advertised Exhaust Duration: 284

Advertised Duration: 284 int./284 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.484 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.484 in.

Valve Lift with Factory Rocker Arm Ratio: 0.484 int./0.484 exh.

Lobe Separation (degrees): 108


I use this truck as a summer driver, and will occasional take it to the strip. This winter, i think i will pull out the engine, and check it over. I want to ensure that the bottom end is sound, and make some changes as required to make it faster than a little red truck.
I know that the intake manifold is mismatched to the cam, and plan on replacing it.

With those details out of the way, i can ask some questions:
What would the recommended cylinder head be for this type of combo? If you subscribe to the Engine Masters basic recommendations, "Buy the best head you can afford" motto, I am wondering if i would be better off with trying to source a later swirl port head, and having them rebuilt (likely about $1000 or more with 2.02 valves) or going with a Indy LA-X or Edelbrock performer head? Machine work is very expensive in my area. The cost of machining would narrow the difference down substantially, making the LA-X head quite interesting to me. Actually more specifically im interested in the INDY/IMM SB Mopar Heads.

Since this will be a mostly street driven unit, At what point does the larger port volume start to affect drive-ability?
Is this camshaft even big enough to fully make use of an aftermarket head? or would i be better off to try to port the old J heads myself?

What kind of cranking pressure should i have if this engine truly had 10-1 compression?

And finally Intakes...... Is the edelbrrock performer or performer RPM a better choice for this heaver vehicle? Is there a vintage made dual plane manifold that would be a good choice? I have really begun to dig the older "Just stepped out of the 90's" look of this truck. and for that reason, i thought i would try keep the offy intake, but it is a hindrance.
Im going to put up another post in drive trains to help me identify, and choose a proper stall converter for this unit

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First off, quit screwing w/ it , and send it to me .

Second , I`d ditch that intake in a heartbeat , sorriest design I`ve ever seen .

Third, trickflow alum heads and intake ----------jmo