317 Heads?
Thread Starter
Pro
Joined: Nov 2004
Posts: 601
Likes: 1
From: Wa
317 Heads?
I am picking up a set of 317 6.0L Heads or called the LQ9-LQ4 heads for cheap and having them milled .030 to bring the cc's to the same as the LS1 heads. Should i have them ported too? I am putting them on a 98 MN6 coupe and adding the TR224 cam. I have noticed there isn't too much about the 6.0L heads on this board. There the same as the 243 heads but with bigger combustion chambers 72cc vs 64cc 243 heads. Just thinking should i have them ported or throw them on as-is?
Thread Starter
Pro
Joined: Nov 2004
Posts: 601
Likes: 1
From: Wa
Well i don't see much on here about them even for forced induction. I can get a set for 150 bucks and spend 50 bucks on getting them milled .030 to bring cc's to 67.66 same as the Ls1's and save 300 bucks not getting 243 heads and they flow the same.
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I think there might be some valve clearance issues because the 317's have a bigger combustion chamber, not just a thicker deck. When you deck the heads you bring the valves closer to the pistons. It will depend on which cam you go with, but I believe that 243's are better on the 347 motor. There was also some talk of squash area at the top of the piston with the 317's not being as efficient at the 243's due to different combustion chamber (for the larger bore 6.0l). Someone with more experience can confirm.
Le Mans Master
Joined: Jan 2001
Posts: 5,786
Likes: 6
From: Lafayette Colorado
For how well the L92 heads flow out of the box, I do not see any reason to have a set of LS1, LS6, or LQ4 ported. The L92 heads flow better and are cheaper than any ported set of heads I know of.
Keith
Keith
Thread Starter
Pro
Joined: Nov 2004
Posts: 601
Likes: 1
From: Wa
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Le Mans Master
Joined: Jan 2001
Posts: 5,786
Likes: 6
From: Lafayette Colorado
