317 Head Valve size
12-14-2023, 11:50 PM
#2
TECH Senior Member
Intake- 2.000"
Exhaust- 1.550"
As per Summit database
Exhaust- 1.550"
As per Summit database
12-16-2023, 03:41 AM
#3
Same as the LS1/6/2.. Any gen3 LS that came in a car. So intake is 2.00in and exh 1.55
The 317 head was the starting platform for the LS6 243s. Besides the lightweight valves, the only other difference is larger chambers.. 317s being 71cc (70.5 to be exact I believe vs most data found being rounded up to whole#) vs the 243 LS6 heads being 65cc. So you could mill the 317s some to have 243s with slightly more compression in your engine, yet not as high in case you want to run mid-grade octane etc yet make more tq than being 71cc and still flow identical to LS2 head since still having solid valve stems.
The 317 head was the starting platform for the LS6 243s. Besides the lightweight valves, the only other difference is larger chambers.. 317s being 71cc (70.5 to be exact I believe vs most data found being rounded up to whole#) vs the 243 LS6 heads being 65cc. So you could mill the 317s some to have 243s with slightly more compression in your engine, yet not as high in case you want to run mid-grade octane etc yet make more tq than being 71cc and still flow identical to LS2 head since still having solid valve stems.
12-17-2023, 07:55 PM
#5
Same as the LS1/6/2.. Any gen3 LS that came in a car. So intake is 2.00in and exh 1.55
The 317 head was the starting platform for the LS6 243s. Besides the lightweight valves, the only other difference is larger chambers.. 317s being 71cc (70.5 to be exact I believe vs most data found being rounded up to whole#) vs the 243 LS6 heads being 65cc. So you could mill the 317s some to have 243s with slightly more compression in your engine, yet not as high in case you want to run mid-grade octane etc yet make more tq than being 71cc and still flow identical to LS2 head since still having solid valve stems.
The 317 head was the starting platform for the LS6 243s. Besides the lightweight valves, the only other difference is larger chambers.. 317s being 71cc (70.5 to be exact I believe vs most data found being rounded up to whole#) vs the 243 LS6 heads being 65cc. So you could mill the 317s some to have 243s with slightly more compression in your engine, yet not as high in case you want to run mid-grade octane etc yet make more tq than being 71cc and still flow identical to LS2 head since still having solid valve stems.
It's time for a little change up I guess.
12-18-2023, 06:01 PM
#6
11 Second Club
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