To the experts, I have a cam @ .050 is intake .442, exhaust is .465 and duration is 214 and 224. Oh almost forgot I got 1.60 rockers so that is .471 and .496 and duration is slightly higher by 2-4 degrees, so Ive read. I have a 383 strocker and plan on a Holley 750 universal vacuum secondary. Intake will probably be rpm airgap. So the big question I can't figure out. By the way rear-end is 3.42's, What rpm stall for my 700r4 with a transgo kit, auto and manual, will be best for my power band. Please experts give me guidance. It will be a weekend warrior iroc and if i'm pleased I'll go to the track.

 

There's not going to be any kind of "optimum" converter... the motor is too mismatched.

You have the legendary "mild" cam (one step up from the equally legendary "RV" cam). The super el cheepo from Summit or wherever, that's been around since the early 70s. In a 383, it'll idle like Grandma's grocery cart, and pull HARD from about 1000 to 4000 RPM, and be completely done by the time the engine reaches any kind of RPM where the intake would make any difference compared to stock. It'll flow MAYBE 500 CFM before it tops out, so a 750 is too much carb.

A stock S-10 converter (2200-2400 behind that combo) is probably all it'll be able to stand.

That's too much intake and too much carb for the cam.

What heads have you got? Is this motor built yet? Too late to pull that weenie thing out of there and get something better? As cheap as cams in general are, why poison a couple thousand dollar job over something that only costs about $100? Is $100 worth cursing at this thing every time you think about it?

 

Thats what I was afraid of. When I built the motor it was to be a lillte better than a stock tpi but since I never got it on the road I wanted to really beef it up and put on a carburetor. I currently have cast heads with 2.02 1.60's. I have not het bought anything as far as an intake and carburator yet. I would greatly appreciate your opinion on a cam swop, what numbers with 1.6 rockers, what intake, carb 750 vs, and what intake and stall converter. I thought I would hear a reply as you have given Sofakingdom, thanks for being honest. I have no problem pulling the motor for a cam swap among other mods.

 

What heads are they (casting # if GM or model # & chamber size if aftermarket)? What other work has been done to them besides just cutting out the valve seats? What pistons are in the motor? The goal would be to match everything else to those things...

 

The heads are actually 305 castings that have been ported and gastket matched. I don't have a casting number on hand but the chamber size would be stock casting I believe 64cc, if that sounds right to you. The 383 kit was an eagle kit with Keith black forged pistons, with cut outs, not flat or domed if that makes sense, I'm at a lose for words. I really appreciate your input as I'm trying to figure out the best parts match to open up this motor as a weekend warrior and occasionally the track.