Ok,

My buddy just picked up a 383 longblock, complete from carb to pan. It is a stock 350 block from 77-79, and stock heads (I think). We ditched the carb, and the heads, intake, cam are soon to go. The CR is about 9:1, and the crank is forged, balanced rotating assembly, complete with flywheel. This is going into an '85 Z28, and the computer is gone. He is willing to get new pistons if needed.
My question is this: what combo should he get? What is the best bang for the buck?? Now he's considering the Trick Flow combo good for 500 hp with a Vitor Jr. intake. I told him he should mix and match for better combo. He wants a lot of power, but decent streetability (mild lope is ok).
Any help here would be great.
Thanks in advance.

--Dave

 

put at least 10 to 1 pistons in it and also get forged

 

Sounds good, anyone else?

 

Compression will vary according to the cambers of the heads...

to make power you need a good cam ...no mention of that???

If I were you....get a PKG deal.... go with the Edlebrock Victor JR... heads, cam, and intake... then run a holley 650 or 750 DP carb.... with a good HEI... that will be close to your GOAL!

OH... run hooker super comp header... so you can breathe on the big end....or at least large tube SLP headers....

With that you will need a 3000 stall or better unless you run a manual....

at least a 3.42 gear would be nice.... 12 second street car no problem....should go 11's with suspension mods...

 

with your 383- your compression is too low, take off the heads and see if you have flat tops, or dished pistons....

If you have flat tops- your ahead of the game, since you dont have to spend money on pistons, use the money you were going to buy pistons with and add it with the money for new heads and buy a set of AFR 195cc heads for $1200 or watch ebay. These heads are INCREADIBLE. i had a set on my S-10(sold it) get them with 64cc chambers and it will bump your compression to around 10.5:1

Dont let anyone tell you you cant run 10.5:1 on pump gas, I ran 11:1 without problems on 93 octane.

as for a cam, look for something with 225-235 duration @.050 with over .500 lift. (since your heads have good springs now)

get a set of hooker super comp headers #2210, and dumps to be cheap

So you have about $2000 in stuff, but let me tell you...the car will RIP...or just buy a nitrous kit for $500...

Or do mods and nitrous.... its the american way "Bigger, better, stronger and FASTER!!

 

If he has stock heads right now, they are most likely 72cc. Going from a 72cc head to a 68cc AFR will put him around 9.4:1 compression, nowhere near 10.5:1.

 

Your right, I was figuring for true flat tops, flat tops have something like -6 cc for valve reliefs. Assuming head gasket bore of 4.08" with a .039 thickness, and that the piston sit .05 below deck the compression would be 9.8:1 with 64cc(or 9.45 like you said with 68cc) but AFRs have extra thick decks, have em milled to 58cc which would bump you to 10.47:1

my bad for assuming

 

Whats the budget, If its not to small you might want to consider a super/turbocharger setup. Get lower c/r pistons some decent heads a blower cam.... yada yada, turbo will give you better gas mileage w/ power up high, super you can change the boost by changing pullies if you want to race or just drive around.

 

I think for now a boosted application is out of the budget. He's just looking for ~375-400rwhp. I know it can be done with a carbed 383, just looking for some good ideas. Thanks for all the suggestions so far.

 

Then I would definatly raise the compression some, that 9:1 will hurt you from gettting maximum power with the setup you have, although you might save a bunch in gas in the long run, you wount have the power you could. For example my engine has an 8.3:1 and if tuned perfectly I will only be able to get around 430 horsepower out of it. If it was 12:1 I would be getting over 500
Then again im running fuel injecton with alum heads so I can have that high of a compression no problem

 

The new heads will be aluminum, that has already been decided. Its the type/brand that is still up in the air. Also, does having a carb hinder your ability to run high compression?

 

Carb gives you more power than TPI, period. There is no limit to what you can run on a carb. (unless you spend $1400 on a mini ram setup)....now you have to decide on an intake...

IF you want max hp, there is no question AFR is the only way to go..you can stop thinking....

see:Head Flow comparison

You can get a cheaper set of heads that wont flow as well. Be sure not only to check out the peak flow #'s, but to look at mid-lift #'s (.400, as your cam is at max lift once, and .400 twice as it opens and as it closes)

I LOVE MY AFRs, and you will too!! Airflowresearch.com

195cc should be good if your not going crazy, 210s if you are. Call afr tell them exactly what your doing and they will make sure you get exactly what you need!!

 

Carbs hinder what c/r you can run, but you are better off going with a carb than tpi because tpi is very restrictive. My car on the otherhand has a good fi setup so I am better off with my fi than a carb, and the LS1 intake is just godly....
As for the heads I agree withSweets10v8 in definatly not just looking at the peak flow #'s, but the mid-lift #'s as well. If possible get a few that you want to compare to when you pick out anything and run it thru desktop dyno2003. It wount be exact, but It will give you a good idea and many people say its very accurate.

 

If he changes the pistons, the assembly is no longer balanced. The chances of him getting another matched set the exact weight are very low.

 

Just thought I'd give an update. He has decided to go with the Vortech head/Air gap intake package from SDPC because I will save him money for the accesories (carb, water pump, starter, etc.) I was thinking that these heads may not be the best for a 383, but thats what he wants. They are machined for .550" lift. We called Comp Cams for a cam recommendation. He recommended the 12-246-3. 230/236 duration @ .050 lift, .490/.490, and a 100* LSA.
I was just wondering if this will do the trick with some 1.6 roller rockers. Must be semi streetable, but a good lope is ok. The goal was 12 second 1/4 mile. Its a 85 Z28, BTW.

--Dave