James71Cutlass

Picked up the original rocket 350 from my '71 Cutlass S car a few weeks ago. I have taken a part the top end of the engine as it sat for a while. Everything looks good from what I can tell. My mechanic said he will put it back together. I'm not looking to make this a race car but seeing as the top end is already a part I might as well try and get some more horses out of it. Currently I have 2.5 inch duel exhaust, turbo 3 speed trans with 3.42 gears in the rear end.

I'm going to buy a 4bbl intake and a new carb. What cam should I look at getting for performance. Should I put in better lifters ect?

Thanks.

Sugar Bear

Replace the timing chain and gears for reliability and increased performance. A stretched chain will make the valve timing late, a worn cam gear can make the chain jump, possibly bend valves and clog the oil pump intake.

Fun71

I don't know what you mean by "better lifters". A new cam requires new lifters, so get a set along with the cam.

Be aware that the 71-72 350 engines have fairly low compression to begin with due to the pistons with HUGE 24cc dishes so it is easy to overcam the engine, meaning you have to be conservative with the camshaft.

If you took the heads off and reinstall with thicker composition head gaskets (like Fel Pro) the compression ratio will be even lower due to the thicker head gaskets. You can compensate for this by milling the heads, but it still won't get you out of the 8:1 compression ratio range. So again, be conservative with the camshaft.

James71Cutlass

Will do. Thanks for that.

James71Cutlass

By better lifters I mean hydraulic. Thanks for the other suggestions.

Sugar Bear

The lifters are hydraulic, if the valvetrain wasn't tapping leave the lifters in place unless you are replacing the camshaft. Used lifters must be put back in the same bore they came from; otherwise it will wear the camshaft faster.

Good luck!!!

James71Cutlass

Ok thanks that. Yes, I plan on replacing the camshaft so I will buy a new set of lifters.

Sugar Bear

There are lots of options and potential pitfalls with cam selection. I'm not the one to select what cam spec but other forum members can help, one in particular is Cutlassefi. Seek his advice and others about what spec, it makes a huge difference.

If the heads are off have them leak checked at a machine shop and replace the valve seals.

cutlassefi

Your cam choices are very limited if you’re staying with the stock pistons. I wouldn’t put too much effort into that.
I’d start by putting in a new chain, dual exhaust, and a good tune. That’s your best bet.