317 heads on 5.3?
317 heads on 5.3? I'm doin the usual swap on the 5.3l for boost swapping in 317 heads... Now ,would ?I run with valve issues if I milled the heads .20 and use an aftermarket headsgasket cometic instead using .51 thick ill go with .30 thick. My reason of doing this is to keep the CP up ,keep hearing to prevent blowing off the head gasket to run a thin gasket..
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
I'm doin the usual swap on the 5.3l for boost swapping in 317 heads... Now ,would ?I run with valve issues if I milled the heads .20 and use an aftermarket headsgasket cometic instead using .51 thick ill go with .30 thick. My reason of doing this is to keep the CP up ,keep hearing to prevent blowing off the head gasket to run a thin gasket..
The only reason 317s are widely used on boosted engines, is to lower the compression ratio due to their larger 72cc chambers.
find an online compression ratio calculator and run the numbers for your engine spec's and see what you come up with.
The 317 heads require a 4" bore gasket to seal properly, the most popular available for boosted applications are the LS9 gaskets and are around .050"
compressed thickness.
On The Tree
Joined: Oct 2007
Posts: 121
Likes: 0
From: Grapevine,TX
I'm doin the usual swap on the 5.3l for boost swapping in 317 heads... Now ,would ?I run with valve issues if I milled the heads .20 and use an aftermarket headsgasket cometic instead using .51 thick ill go with .30 thick. My reason of doing this is to keep the CP up ,keep hearing to prevent blowing off the head gasket to run a thin gasket..
Just my opinion from my experience with them. I have run 15 psi with the 862 heads with zero problems. No inter-cooler just E85.
