marcus_booth

Hey guys whats the best cam for gaining power on a stock 1989 rs 305 tbi without changing out the springs? I hear flat tappet is better than roller but i know very little about this topic. I know high lift and such is good, P.S im looking to spend under 100$ on this But if you know something more expensive that will turn big power let me know.

Thanks!

dmccain

iTrader: (2)

Roller is better and you are already setup for it. Get a stock L98 or Lt1 cam in it and get a chip tuned for it and you will be safe on springs and make a bit more power.

cosmick

There are no roller cam swaps under $ 100 that keep the stock springs unless you get a used stock GM cam, like the LT1, but that's a really bad match to your swirl-port heads. The LT1 cam is slightly more lift than the L98, both have the same late intake closing that swirl-ports don't work with. Your best money is spending $200 on Elgin's E1136 HR, 210/215-110 462/470. If you go non-roller, then by the time you buy lifters, an extra oil filter, a case of ZDDP oil, and the lube, you'll be up to $200 anyway, but you'll have to run ZDDP oil forever after.

dmccain

iTrader: (2)

Honestly if you want power you are held back by your cu. in, your fuel injection, your heads, your cam.. the list goes on and on. Enjoy the lil 305 while building a 350 if you want power. I probably wouldn't sink a lot of $ or time in the TBI 305. I like mine its great on gas, sounds good, and I haven't hardly had to ever turn a wrench on it unless it was something I just wanted to do.

The Project

iTrader: (6)

Used stock LT1 cam will work fine for your application...lots of members on TGO go this route.

Your 89 is a roller block from the factory.

Hawke

LT1 cam or summit 1104 cam. That is what I am planning on my 305.

julian260

I run a hot cam in my carbureted 305

Arctic White 91 RS

Marcus, given your car is almost 28 years old and probably has nearly 100,000 miles on it, when doing a cam change a new set of valve springs is a good idea. Springs are inexpensive. If new springs break the budget, I would seriously re-think doing a cam change. For the new cam to give best performance the exhaust system should be improved too: Headers & Y-pipe

tom3

Put on a set of high ratio rocker arms. Stock is 1.5 : 1, common upgrade is 1.6 : 1, little math will give you the added lift numbers, some extra duration too. Changing a cam is not a job to be taken lightly, especially with the engine in the car. Put a Flowmaster (or similar) muffler on it while you're into it.

The Project

iTrader: (6)

I now run a ZZ4 cam with 1.5 Comp Cams (CC) FULL Roller Rockers, CC behive springs and CC screw in studs. No issues.

...and a Borla exhaust