Evaluate this 383ci combo

[Sweet72]

New nodular cast 383 crank
Speed-Pro Hyper. flat top pistons
4340 I-beam 5.7 rods full floating pin ends
Sealed Power moly rings
Dart Iron eagle heads, 64cc chambers, 200cc runners, strt. plugs
3970010 '72 350 4-bolt block
Holley 600 double pumper vac. secondaries
Hooker Comp. headers
Felpro gaskets

According to Scoggin Dickey catalog, should have about 10.3 CR.
I'm open to suggestions on the intake and camshaft, and any and all suggestions are welcome. I'm hoping to make good low and mid rpm torque with this motor in the '72 GMC. Oh, and as for a camshaft I'd like to keep some vacuum, but want a little lope for "effect". Anyone tried the new Nostalgia Plus cams from Comp? Thanks
-Sam

[PICKMUP]

Our trucks are pretty heavy. For low to mid rpm torque and today's gas, it might work better with a piston giving closer to 9:0 compression ratio.

[rn2fine]

You may want to consider a smaller intake runner on the heads if you are looking for good low to midrange power and torque. Smaller intake runners make low end power. Big intake runners make high end power. If it were me I would stay under 200 given your somewhat mild aspirations for a cam, your carb size 600cfm, and your desire to build some low end to midrange power. Maybe compromise with a 180 to 190 sized runner. Just my 2 cents worth. Good luck with your project and I hope it all goes well.

[Sweet72]

You guys are awesome! I haven't ordered the stroker kit, cam or heads yet, and am hoping to get this thing right the first time. I can't afford to experiment with heads costing $459.95 ea. + shipping. A 72cc chamber 180cc runner head is also offered.

[dallas71]

If you are buying the heads now why don't you take a look at the Vortec heds??? You can buy a set of the for around $550 and they will gave the same performance without the hefty price tag....

[rn2fine]

180cc head would be good and a 72cc chamber would give you a little lower compression ratio as someone had previously suggested. As another member pointed out vortec style heads are a good option as well with 170cc runners and 64cc chambers. A lot people have had good luck with the vortec style heads. Vortecs provide great power for the price. I myself tried some vortec style heads and had a few problems with coolant leaks. There are a few posts on other boards on the web about the problem and a several GM mechanics that have told me that it is a common problem and that they are changing intake gaskets on them often at the dealerships. I am now using Edelbrock RPM aluminum heads w/ 170cc intake runners, 70 cc combustion chambers, and straight plugs. They sell for between 880 and 980 a pair. I have also heard good things about the AFRs: www.airflowresearch.com

Good Luck and Have Fun with Your Project

[Warrens69GMC]

Your combo looks good:
the 72cc heads with 180cc - much better choice
comp cams dual energy 265 would be my choice for the cam.
performer rpm or airgap manifold
warrens69gmc

[Sweet72]

ttt
Any other cam and head suggestions???

[canadianchevy72]

Edelbrock performer rpm airgap and Comp Xtreme energey 268 cam. You should still make decent vacumn numbers with that cam.

[72C203503ONTHETREE]

The reason the Vortecs leak is that the gaskets use a plastic backing with a silicone bead applied around the ports and water passages. The plastic cracks and causes leaking at the water passages either to the exterior or to the inside of the engine or both. I have the Vortecs on my 83 El Camino and no problems yet. You can get the whole kit-assembled heads, Performer or RPM intake, rocker arms, head bolt set, all gaskets, and a few other things all for around $700 from Pace Chevrolet in Ohio. I am going a little wilder with mine, I'm planning on getting Brodix Track 1's or similar with a nice solid roller cam, Victor Jr. style inbtake, 600 cfm Carter(will go bigger later), racing HEI, Racing aluminum short water pump, etc.. If you use aluminum heads you can get by with 10:1 compression. The weak link in your set up is the hyper pistons, they are a little stronger than plain cast but won't be able to stand up to high rpm for long or any kind of forced induction, and especially no decent hit of nitrous. You can probably go to near 6,000 rpm with not many problems, but depending on the cam you choose, you may not get that high anyway. By the way, stock Vortec heads can't have any lift over .480 so make sure you don't over cam the heads. You can get them with better springs for a bit more. You can also get them in aluminum with 200 cc intakes from Edelbrock. As far as intake, the RPM air gap is good, and a Victor junior(unported) will give you good mid range and top end without losing low end. Victor Jr's come with smaller ports so that someone can port them the way they want, all the way up to Nascar engine builders needs. You have plenty of room for the taller intakes plus a 5" filter. The Holley you are talking about is not a double pumper if it has vacuum secondaries, it is most likely a 3310 center hung float vacuum secondaries, it is a good carb but I would at least use a 700 cfm on a 383. A 700 4150 true double pumper would be the best for performance once you get it dialed in. If you can afford it, get a Barry Grant Speed Demon. They are better and look nicer also, they have four corner idle mixtures, smoother flowing venturis, etc.. They are not cheap though. When you install the headers, throw away the crappy paper gaskets and use either copper or aluminum gaskets, they will never leak or blow out, I know this from experience. They will cost about $40 but will be worth more than thier weight in gold after replacing many asbestous gaskets and skinning too many knuckles.

[Sweet72]

72C20350THREEONTHETREE,
Thanks very much for your input. The holley I have is a #R84010-2, if that makes any difference. This engine will not see nitrous or a blower. I plan to use it as a occasional driver with more than the average in the cohones department. I thought the Vortec's require a special intake. Never gave them much thought, since I wanted to go OldSchool on this engine. Ok, I'll take a look at the vortec setup at Pace Chevrolet.
P.S. I won't be racing the truck and it has a 3.07 rear, I know, they suck...but for gas mileage they're great.

[72C203503ONTHETREE]

Yes, you will need a specific Vortec intake since the bolt holes are completely different, the center two bolt holes on each side are not on Vortec heads and the angles are different for the ones that are still there, more of a straight up position than the angled ones the older small blocks used, almost like a 302 Ford type. You also have to use self aligning rockers unless you get some guideplates put on the heads. I am not familiar with the specific Holley part numbers, just the styles and cfm. You won't need anything too big if you dont plan on racing it or using forced incuction/nitrous. The 600 carb will do fine for you then, especially with highway gears, lol.

[lewi]

Sweet72...your looking at what I am currently in the process of. I'll be picking up the motor on Tues or Wed.

For the reasons stated previously I went with the 180cc runners on the Dart Iron Eagle heads. My compression ratio is 9 to 1 although I am running an Edlebrock Carb it is also 600cfm. All this said you are after a very simular result to myself. I spent quite a bit of time evaluating what I wanted and ask alot of questions, including many here (thanks to those who helped). I believe like others have said you may want to keep the ratio down a bit unless you plan on racing. In any case good luck with your project!

[Sweet72]

Thanks to all who replied! I have decided to go with the Dart Iron Eagle heads 180/72's W/2.02-1.60 valves, Comp XE268H and Edelbrock Performer RPM intake.
lewi, Let me know how your motor works out.

[crazy longhorn]

That should have some real good "kick" on the street! i run an XE 268 in my 383, & with edel RPM heads(170 intake runners), & 9.8 to 1 comp ratio ,she is true street. The little mill pulls 15-16 inches vac @ idle, with a slight lope & pulls like stink from just up off idle , to about 5700. There is nothing sweeter than a really flat tork band in a heavy truck Good luck,crazyL

[Dean23]

check this site out there are some good combo's

http://www.ryanscarpage.50megs.com/combos1.html

[rn2fine]

Nice choices Sweet 72.

Good Luck !!!

[bigjimzlll]

Ive noticed that most of the Dart IE heads need some bowl cleanup..The intake valve seats are prettly jagged. The new set of 230's I just bought ahd abot 1/8th of an inch overhang. Its onlt about 75 bucks to have a shop clean them up..and can mean 30-40 HP. I always suggest buying the heads bare(unless they are AFR or Brodix) and have your local shop assemble them. A little more personal QC