ultraspeed

Will there be any issues installing 208 valves in the 317 heads and putting them on a 5.3 LS engine?

bww3588

iTrader: (49)

Why would you want to? If it even fits in the cylinder without the valve hitting, it would be so shrouded it wouldn't help any anyways. I could see you losing a good bit of power vs the same heads with a stock sized valve.

Not to mention your will have to mill the heads so much to even get a respectable compression ratio on a 5.3, that it would further amplify the shrouding problem.

KCS

iTrader: (20)

It could work, but as already mentioned it probably isn't a great idea. The compression will be low and the intake valve will be jammed up against the cylinder wall pretty tightly, it may even contact when the engine is running. There's way to work around it all, but its more expensive than just getting a more appropriately sized head in the first place.

batboy

iTrader: (6)

Didn't realize you could squeeze 2.08 valves into 317 heads. On a 5.3 motor, about the max valve size is 2.02. Anything bigger causes major shrouding problems (assuming it'll even fit).

KCS

iTrader: (20)

I've already put much bigger in a 5.3L head. There's room to go pretty big, but you have to replace the seats. Now as far as the small 5.3L bore, a smaller valve is more appropriate.

I'm slowly making progress on a set of 243's for my engine. New seats are required.

wildcamaro

iTrader: (15)

317s on a 5.3...I hope you have a turbo! The compression ratio is prob gonna be less than 9:1...what's the reason for those monster intake valves?