Hello

I'm looking for a camshaft for my 350 TPI. Specs are:

89 350 L98
Vette 113 heads ported and polished
stock TPI (carburetor or HSR soon)

the car has got headers 1 5/8 and T5 trans connected to the 3.73 rear end

I'm thinking about LT4 Hotcam or Comp Cams 502 (both with 1.6 rockers) but maybe another more agressively cam?

Second, I don't know which valve springs are correct for heads w/o machining? Can anyone help?

 

stock heads take a 1.25 spring. The tpi doesn;t like big cams . But the stealthram will. So picking a cam for one , won't be the best for the other

 

If you have TPI now, you HAVE to go with a stealth ram and an LT4 cam. That is an awesome setup and the cam works good with carbs as well.

I used a set of PAW valve springs on the last Chevy I built. They were single springs good for .600 lift. You can look them up in their catalog easy enough. Just don't forget to make sure that you have enough clearance to keep the tops of the valve guides from contact. It knocks the keepers off of the top of the valves and then you drop a valve.

Don't ask me how I know that...

 

will these springs are good for hotcam and 1.6 RR?

COMP Cams Valve Springs: CCA-983-16 - summitracing.com

thx

 

I would look up the specs for the LT4 springs and then compare them to the ones that you want to buy.

They don't look right to me but I am NOT an expert, although sometimes I feel like one!

Anyway, I can't tell unless someone tells the lift that they are rated for. I'm not deep enough into the math yet to be able to tell how well they will do for a given application when all they tell me is a pressure rating!!

Sorry!!

 

Hotcam is .525" lift on both intake and exhaust with 1.6 rockers. If your heads and springs can take it, it'll work.

On the one set of aluminum Vette 113 heads I've worked on the retainers hit the valve guide seals at only ~.470" and the stock springs wouldn't like much over about .500"

I'm told that later ZZ-4 heads (which are just Vette aluminum heads but on the GM crate motor) don't have this limitation as badly, but I can't confirm that personally.

 

After 1988 they were a "D" port design.

 

I understand the lift of the cam but sometimes the lift that the springs can handle is listed with them in the catalog - that's what I meant.