i was wondering can u use the ls1 intake on 243 or 317 casting heads and if you can is it better also was wondering are the 317 the same as the 243 right just has a larger combustion camber 64 vs. 72 if i mill the heads on a 317 would they be better ?

 

The LS1 intake will bolt up and work, but a LS6 intake would be better. Yes, the 317s have the same ports as the 243s. The problem with milling the 317s for more compression is that you would have to remove .045"- .050" just to have the same size chamber as the 243s. That would reduce your piston to valve clearance by quite a bit.

 

The 243 heads would work better for you. We have have new GM castings for $395 per pair bare. We would suggest to go with a LS6 intake also.