How does this 360 build sound?

[JLDupreeIII]

I am trying to figure a good build for when I finally get back home. What I am looking to do is have a streetable ride thats is pretty quick off the line, sounds nasty, and runs on pump gas... I have not had the time to crack it open so I am not sure what is going on inside, but I hope for the best. I runs good minus some electrical probs and an exhaust leak, but that will all be so much easier to handle while the motor is out. I am relatively new to this so if there is something I want to do that is unneccessary please let me know.

Static C/R: 10.6:1, Dynamic: 9.5:1
per: http://kb-silvolite.com/calc.php?action=comp

360 bored .030 over, decked, honed
KB107 Hyperutectic pistons
MP P4120231 "purple" camshaft
Rebalance, blueprint
*should anything else be done with the bottom end?
*would this provide enough quench to make the C/R ok for pump gas?

Heads, type currently unknown...
Bowls blended, ported, polished, clean runners, 2.02 valves, port matched
*are stiffer valve springs neccessary? What else should be done here?
*are valvetrain upgrades needed for these choices?
*will I need to replace the pushrods or anything else?

Edelbrock Performer RPM intake *came on car already..., I heard torkers were gabbage?
Edelbrock 750 CFM carbureretor *also already on the car, is CFM good?
TTI headers *the ceramic looks good but man, $$$, currently has manifolds
3" custom exhaust w/ "X" pipe *already on the car, overkill?

The misc. list:
True-roller timing chain
Disc brakes (front) *any suggestions, please?
New wiring harnesses (all)
Fiberglass hood,bumpers,go-fast wing.
Tilt steering wheel (forgot the brand... looked nice)
Those black headlights look cool but I think they are illegal...
that rear suspension replacement I saw in here was awesome... maybe one-day.
...This is turning into a wish list, sorry...

I have a 727 already in the car w/ 8-3/4 3.55 posi. I heard there were different 8 3/4 rears, some good some bad but I cant find any mention of posi... just sure-grip? Same thing? I think I could use O/D but that can wait. Would I benefit from more stall, shift kit, throttle body, or anything? When I get out of afghanistan I am gonna tear it down pretty good and I want to get everything so I don't have to go back and re-do stuff later. The car is not #s matching and build tag is missing anyways so I'm not too concerned about any of that...

 

[rumblefish360]

JLO, welcome aboard. I'm going to address your post with bold type latters, not yelling here, it's just easier to insert the answers within your post.


So here we go.

I am trying to figure a good build for when I finally get back home. What I am looking to do is have a streetable ride thats is pretty quick off the line, sounds nasty, and runs on pump gas...

I am relatively new to this so if there is something I want to do that is unneccessary please let me know.

Good idea to seek opinions. I see a game plan here. Wise move to make one. Now, once you finalize it, stick to it or it'll end up costing you more money.

Static C/R: 10.6:1, Dynamic: 9.5:1
per: http://kb-silvolite.com/calc.php?action=comp

360 bored .030 over, decked, honed
KB107 Hyperutectic pistons
MP P4120231 "purple" camshaft
Rebalance, blueprint
*should anything else be done with the bottom end?
*would this provide enough quench to make the C/R ok for pump gas?

Compresion ratio looks good for a taget goal to run with iron heads
I run those KB-107 pistons. Should you need a overbore, have the machinest run a torque plate on the block to simulate a load, like a cylnder head is on top and then bore the engine. Pay attention to ring gap size on Hyperutecic pistons.

The Purple cam shaft is 241 @ .050.This may be a bit steep for the 3.55 gears.
A rebalanceing is a must and blue printing is excellent, but may not be needed. It would be an extra step worth while.
The bottom end seems to have met the basics so far. A new oil pump. A HV pump not needed. New rods would work out cheaper then rebuilding OE units.

The final comp. ratio is dependent on head selection and it's chamber cc amount and chamber shape. In general, I'd say yes, but it needs to be looked at closer IMO before I commet to a definet answer.

Like I said, I run thos pistons. And I ran them with iron J heads and Edelbrocks.

Heads, type currently unknown...
Bowls blended, ported, polished, clean runners, 2.02 valves, port matched
*are stiffer valve springs neccessary? What else should be done here?
*are valvetrain upgrades needed for these choices?
*will I need to replace the pushrods or anything else?

In general, it's a good direction you have listed. But the level of porting is dependent on the cam shafts lift and intended useage. Considering the cam is only a .484 lift, it'll need nothing more than a bowl blending and other basic porting mods.

When you purchase a cam, the seller, ethier MoPar or the manufacturer like Crane or Comp cam etc... will have a recomended spring to use with the cam. Purchase them with the cam.

Comp Cams, just for example, will have a package set up with any of there cams that can include just springs to everything needed for the head and cam use in one package deal.

You may very well have to replace the pushrods. This depends on if the blocks deck is milled, heads deck is milled or the cam size (lift) is large or the base circle of the cam was reduced to allow the size of the cam to fit the block.

Various places sell pushrod checkers. These adjustable pushrods with markings to measure the length of the pushrod. This will tell you if you need to purchase new pushrods or not.

Edelbrock Performer RPM intake *came on car already..., I heard torkers were gabbage?
Edelbrock 750 CFM carbureretor *also already on the car, is CFM good?
TTI headers *the ceramic looks good but man, $$$, currently has manifolds
3" custom exhaust w/ "X" pipe *already on the car, overkill?

Keep the RPM. The Torker line is best left alone for street useage. They can be made to work and well if used right. But for the most part, that old intake should be left on the shelf for what your planing.

The Edelbrock carb is fine until cams get big. (Race styled cams) While they look like the old AFB/AVS carbs that came stock, there a little bit updated wth revised circuits for larger cams other than stock ones. Theres enuff cfm there to feed the engine well and perform well.

TTI's are sooooo worth the money over the 1 size fits all units that will cause headaches.
Leave the 3 inch exhaust there. It's a little big, but worth leaving there.
Overall, the pipe size is mostly matched in size to the engines output. Or it's intended useage. Overkill? Not really.

The misc. list:
True-roller timing chain
Disc brakes (front) *any suggestions, please?
New wiring harnesses (all)
Fiberglass hood,bumpers,go-fast wing.
Tilt steering wheel (forgot the brand... looked nice)
Those black headlights look cool but I think they are illegal...
that rear suspension replacement I saw in here was awesome... maybe one-day.
...This is turning into a wish list, sorry...

A new timing chain is a must, it's part of the valve train and a double true roller chain is a great idea.
Disc brakes can be as easy as OE units or OE units from a later year Cordoba. The '79
s have a 11-3/4 inch rotor. You'll need the caliper brackets for there use.
Ask this question seperate in the brake section. Part detale list can get long and is thread worthy by itself. Otherwise, aftermarket units are a little more pricey, and probably worth it to a degree. This is a your choice issue.

Wiring harrness if needed.

Fiberglass parts, that is a your choice issue. It'll be mine if I have the cash for it. Hood bumpers and fenders if I had it my way.

Tilt steering is nice and a your choice.
Black head lights may present a leagal issue you'll have to look into.
You can get 1 inch overbend springs from many places.

(It's allways a wish list until you have it...LOL!)

I have a 727 already in the car w/ 8-3/4 3.55 posi. I heard there were different 8 3/4 rears, some good some bad but I cant find any mention of posi... just sure-grip? Same thing? I think I could use O/D but that can wait. Would I benefit from more stall, shift kit, throttle body, or anything? When I get out of afghanistan I am gonna tear it down pretty good and I want to get everything so I don't have to go back and re-do stuff later. The car is not #s matching and build tag is missing anyways so I'm not too concerned about any of that...

A posi is a GM term excepted as a general term and interchangeable for the term "Sure Grip"
The 8-3/4 rears come with different sized pinion gears. Larger is generally better. Which also is by the way, the larger the pinion gear, the more Newer it is. As in later years. You'll need the housing to match.

I have a 741 case and a 4.10 gear set. It has lived an abuse-ive life behind 450+ HP engines and a 4spd manual trans.
An OD trans would be great. IMO.
More stall in the verter is a excellent idea if you want it all to work at it's best instead of a slug outta the hole. Seek advice when the final engine package is done.

Throttle body? As in fuel injection? F.I. would also be great, but may very well need a different cam. Something ground on a 112 or wider centerline, not the MoPars 108.

When I get out of afghanistan

Make sure you do! Thanks for your service. We'll be here waiting for you.

 

[crackedback]

Buy Dougs D453 headers instead of tti, save some money, same fit and great quality.

 

[JLDupreeIII]

Excellent advice, I gathered nearly everything I wanted to do from these forums and a few choice sites. I never would have considered the connecting rods needing work or the fuel pump for that matter. Is the choice in cam not really what I am looking for? I wouldn't want to change too much in the valvetrain for the sake of a larger cam. The D453 headers, are they as good performance-wise as the TTIs? The TTIs are pretty expensive... Like I said I want to get everything I can for the sake of reliability. Next step is to find a good shop in the Tacoma area, any suggestions?

 

[rumblefish360]

The Doug headers are similar in performance to the regular header except it actually fits. It's a 1-5/8 tube into a 3 inch colector

The TTI's step up from a 1-5/8 tube to a 1-3/4 tube and a 3 inch collector IIRC. There is or I should say, can be a slight advantage to a step header.

Con Rods can be expensive to rework. My last set was a freebie to me and only needed minor work. So they get the go ahead. Otherwise, it would probably be a set of Eagle or Scat rods. For there cost and OOTB matched weight, it really can not be beat unless your doing your own work on the OE Con Rods.

IMO, a new OE feul pump is all you'll need. A HI-PO pump can be overkill so watch which one you get. Carter makes a couple pumps from a street pump upgrade unit that requires no regulators to race pumps that cn overwelm a carb and need regulators and return lines etc......
If you go up in line size to a 3/8th line, get the sending unit with the 3/8th pick up and IMO a new set of stainless steel line @ 3/8th's. You can get the fuel line from "Finelines.com" and other places.

IMO, the cam size is big for an automatic trans, doable, but a little big and the 3.55's do not help alot.

What size tire are you going to end up running?

Is another torque converter with a higher stall in the plans or OK to change out for the set up?

Are you asking my opinion on a cam?

 

[JoeDust451]

I ran both KB107s & KB190s with J heads in 360 builds, one had a XE268H & the other an XE284H & 3.91s vs.4.56 gears, both were strong runners, but hands down the KB190 build was much better, had better quench, ran on pump gas, this was in a full bodied 73 swinger, the 4.56 gears were a blessing with this combo, the converter was still small at 2800, but what a torque monster for a SB, it was .060", topped it off with a 750dp & MSD ignition, it also was a plessure to drive on the street with PS & PBs., this was at 3700ft. Alt., could only amagin how well it would have run at see level.

 

[JLDupreeIII]

The KB190's would run on pump gas? They would have been my first choice but the C/R seemed way too high for that, quench must really make a difference. Are you saying that the KB190s are a better choice for my application?

When you say the cam is too big for my trans/gears, does that mean that drivability will be affected or does that mean that I wouldnt be within my powerband and it would be sluggish from a stop? I should be able to find a ring and pinion set for my rear end if needed, and higher stall should take care of the trans... But I still want to be able to get on the highway.

How big can I run my tires without any cutting involved? Final gear ratio will affect my getting on the highway and acceleration, so going to a manual has been on my mind. There seems to be allot of work involved with cutting the tunnel and drilling the crank, but it seems that it may be worth it.

The Doug headers seem to be the way to go, thanks for that tip.

 

[JoeDust451]

The KB190's would run on pump gas? They would have been my first choice but the C/R seemed way too high for that, quench must really make a difference. Are you saying that the KB190s are a better choice for my application?

When you say the cam is too big for my trans/gears, does that mean that drivability will be affected or does that mean that I wouldnt be within my powerband and it would be sluggish from a stop? I should be able to find a ring and pinion set for my rear end if needed, and higher stall should take care of the trans... But I still want to be able to get on the highway.

How big can I run my tires without any cutting involved? Final gear ratio will affect my getting on the highway and acceleration, so going to a manual has been on my mind. There seems to be allot of work involved with cutting the tunnel and drilling the crank, but it seems that it may be worth it.

The Doug headers seem to be the way to go, thanks for that tip.

I ran the 190s on pump gas with no issues, so have others, i think the XE284H would be a better choice then the .484 MP, it'll have better tuneing ability, better vacuum & better perf., top it off with a Perf. RPM & a 750dp, those 3.55s won't really cut the mustard for what your wanting, i'd run at least a 3.91 gear, but 4.10s would be my choice, you can comfirtably fit a 255/60/15 MT under the wheel wells on a 7" rim with everything in the stock location, this tire is right at 27" tall, honestly, how often will you be on the interstate, it'll still be fine, i would boogy all over town running 55-60 with my 4.56s & loved it, a tad bit too much on the highway yeah, but the 4.10s shouldn't be a major issue, plus you'll be glad you have them come time to do some *** kicking, i tried a set of 3.55s i had lying around on this build just for kicks, it was a joke compared to the 4.56s, ran like poo, so you will be disapointed with the 3.55s, unless your just wanting a cruiser.

 

[rumblefish360]

JL, the 190's are domed and are to much for the street IF you use a small cam. Note that the cam used id the XE284H with 4.56 gears.

Is this the direction of the build?

I have ran the 107's. They will come around 9.8-1, which is high for pump gas, IF, again, the cam is small.

If the cam is to big for the converter and gear, then yes, it'll be crappy outta the hole. That Mopar cam @ 244 is large enuff for 4.10's and a 3000 rpm converter.

You can run a taler tire (How tall I'm not sure) via use of a 70's series tire instead of a 60 series tire. Measure the avialable width and run it in a 70 sries.

For tire diamantions, visit the manufactures web site. BFGoodrich will list not only the metric size, but the overall diameter, and width of the tire in inchs.

 

[octanejunkie]

I love the experience demonstrated here, truly a great site!

I have a very similar build in the planning stages using components I acquired "in the deal" with the purchase of my '71 Scamp:

360 magnum block, bored .030 over, decked, honed
Speed-Pro Piston and Ring Kit Z8KH116CP30
MP P4120231 "purple" camshaft
360 magnum crank, journals polished
Rot Assy Balanced (less harmonic balancer and flexplate)
360 magnum heads
-just back from shop, mag'd, cleaned, new seals, valve job
Built 904 trans with stock converter
EDL Performer RPM Air Gap intake
Carter 4bbl, CFM unk (will replace)
​

Nothing has been installed except the seller had the pistons mounted and balanced on the rods (supposedly.)

I have estimated the static C/R at 10.1:1 using EDL-7327 gaskets and a 63cc chamber volume (also estimated) - obviously there are other gaskets I can use but that won't change things too much...

I was looking at the XE268H kit rather than the purple cam or possibly the 280H Magnum cam (which actually seems very similar to the MP284 I have) - I am open to other suggestions too - but here is MY dilemma:

I have two rear ends to work with, not sure which I want to run all the time

In the car is a 7.25" with 2.76 gears, I bought a SG with 2.93 gears off another forum member and am waiting rto receive to install
In "the deal" with the car I also got all the parts to build an 8.75" (SBP axles though) along with a 741-housed SG with 3.91 gears

If I stick with the 7.25" then any of the 3 cams mentioned in this post may be too big, but I do want something a bit more powerful than your average mild-over stock combo, I want something similar to Comp Cams description of the 280H series of cams:

280H Series – Best for serious street machines. This cam has a
definite rough idle and will sometimes affect power accessories.
It can be driven extensively on the street or raced on the weekends. The 280H needs an aftermarket converter, intake manifold and headers. 9.5 or higher
​

Without overdrive the 3.91 gears seem like a lot to run all the time, we cannot avoid freeway driving out here so that is an issue, but I know the 2.93 gears ain't gonna give me that "get up and go" type launch - either way there is a new converter in my future

I will probably get a new carb when this goes on the road, not sure which way I will go with that either.

I am running manual disc/drum so no issue there but may add AC back to the car, let's see what 1 summer without it is like first.

Ultimately I want it to be pump gas compatible, I might do some mild competition, but it will mostly be a fun weekend driver, spirited driving at that, no grocery getter for me :snakeman:

Looking for cam and overall build advice too, but am not looking to hijack this thread, just here to learn and apply

 

[rumblefish360]

In the car is a 7.25" with 2.76 gears, I bought a SG with 2.93 gears off another forum member and am waiting rto receive to install
In "the deal" with the car I also got all the parts to build an 8.75" (SBP axles though) along with a 741-housed SG with 3.91 gears

Replace the sure grip equiped rear gears in the 8-1/4 with a more suiteable ratio, like the 3.55's and use the XE268H. From there, you could get away with the stock converter though a higher one would launch you much better.

If it is 90% plus street, skip the converter.