Auto Racing: More horse power, rear gear ratio, 77 corvette


Question
QUESTION: Matt, I have a: chevy 350 late style roller cam block with full round seal. 9:73 hypereutectic pistons, molly rings, comp cam shaft duration @ 050, 234/238  lift 539/548, elderbrock heads 64cc chambers, hardend pushrods, roller lifters, balanced and blue printed. Air gap intake manifold eldebrock 650cfm carb etc. If you need to know anything else let me know. Im wanting to know what could I do to increase horse power without having to get inside block to deep maybe heads or cam replace is ok or anything else like that. Can you give me some advise how to gain some horsepower i want to drive on street also but i would like to gain some more horse power. Thanks any advise would be apreciated. Thanks Steve

ANSWER: Can you tell me what vehicle this is going into, what trans, stall speed, rear gear ratio and tire size. It sounds like you have a pretty potent build up but your not matched to your drivetrain and car weight. what type of exhaust do you have? How streetable do you want to keep it and do you want to drag race?

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QUESTION: its in a 77 corvette 390 gears i put a 700r4 trans in it no stall. i want it to be quick but still have some top in and cruise on highway. I was wondering about maybe stepping up cam or am i at my limit for driving dependability. Maybe even better heads to gain some more horse power. I realize there are alot of things I can do but I wanted some advice to change something that would match up with rest of motor and not have to do alot of changes at minimal cost. I was thinking heads maybe and a cam or just a bigger better cam. Wanted some advise on which ones to get to match what I got and know how much horsepower gain i would get by doing say cam and heads and if it will still be dependable like it is now. Thanks

Answer
I wouldn't recommend going any bigger with the cam because you end up with piston to valve clearance issues and then need to notch the piston tops. Those Hyper pistons don't take well to notching. I think you are making decent power. Those heads are a good design but can use a good port n polish to make them better. I sincerely recommend you add a performance torque converter as the stock unit is less efficient and not getting you into your power band quick enough. a 2200-2800 stall would really perk that thing up! The limiting factor is the IRS rear in that car is pretty weak for drag type launches.
Focus on the converter and then a good performance tune up. Did you recurve the distributor to match the cam? Thats worth about 10hp and a bunch of bottom end torque. Remember, torque is what gets you moving, horsepower is for top end speed.

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