its a dumb question. what is the biggest lift cam the stock springs can hold on a sbc..thanks ryan

 

like .460" or something weeny. Just upgrade the springs, they're pretty cheap, and will give you more high RPM snort no matter what.

Real question is how much lift can the retainers-guide boss take.... That's in the same range.

another real question - what are you trying to do?

 

its for my dads 69 chevelle he just wants it a little lumy not to crazy so i just thought they would hold a little more than that as for my bird i have all the right stuff

 

I had a stock spring setup and ran .488" on the exhaust without a problem. I believe the intake was close to that as well. If you want to go with some nice springs, you may end up having to machine your heads to accept them, along with getting new guide bosses as mentioned above.

 

comp 981's run about $60, and will help you run a nice ~.470" cam, with a halfway respectable ramp rate, and let you rev up past 4000RPM.

stock springs from a '69 chevelle are way past worn. In fact, i'd guess they're not original as the valve seats wouldn't be hardened and.... well, we know how that works.

So if it's not stock, then it's hard to say how much lift they'll take, so it's kinda a trick question eh?

 

as cheap as springs are for the stock diameter from comp or lunati there's no reason not to match the springs to the cam. while you're doing it you can trash the factory rotator set up and buy a set of retainers too.

 

Stock springs are weak and use a very thin diameter wire. As such, they can actually take a lot of lift- typically more than .500" before getting anywhere near coil bind. HOWEVER..... you'll slam the retainers into the guides/seals long before that. AND the modest pressure of stock springs is in no way adequate for use with even a mild performance cam.

Comp 981 spring or similar will work a lot better than stock (they are drop-in replacements) and can still handle more than enough lift so they aren't the limiting factor- your retainer to guide clearance will still be.

 

well now im just going to rework some old fuelie heads i got laying around for him and then ill stab home one of my old racing cam's that was too small for me but should work really well for my dad with a good manifold