Bigfly180

I have a 347 stroker and i have gt40 p cast heads with a z303 cam, what kind of valve spring should i run with this combo? Thanks

st pete chad

im not sure you can run that cam with the p heads.on my gt40 heads a while back i think .542 was as big as you could go and thats pushing it.are you 100% sure you wont have piston to valve clearance issue? i think the z cam is like a .552 or a .556.i could be wrong i guess it just depends on what pistons you have

Bigfly180

yea its a .552 lift im hoping it will work i guess ill use some clay and see what size head gasket to use. i just dont know what size spring to use, im prob just going to bring them to HPS and see what matt can do im sure he would know.

$hawn

I might have to go out on a limb here and assume that his 347 has aftermarket pistons with an adequate valve relief for a small 1.84 valve, lol. To answer the question, look in to the trick-flow spring kit. it works well with gt40/p heads, is reasonably priced and comes with all the hardware, even seals...

st pete chad

here is a set by comp that will work

COMP Cams 987-16 - COMP Cams Valve Springs - Overview - SummitRacing.com

st pete chad

yea thats what i said but he dont know what pistons.

st pete chad

to be honest i would not spend the money on the gt40p heads.i would go with some afr,trick flow twisted wedge heads.the p heads are killing your 347

Othic

kenny said he will put them in for you

GNs-r-slow

BINGO!

st pete chad

if you dont have the money for thoes i have some trick flow high ports that are alot better then gt40p