XR274HR-10 in 318

Instead of milling the intake, your machinist should be milling the intake side of your cylinder heads, but the end rails of the intake will probably need milled too. I got to checking and the .050 comes closer to reducing the chamber volume closer to 53 cc's, so plan ahead on your compression before having them milled.


That’s another reason I say just mill the intake manifold. If you are going to mill the head, then you really need to mill the China wall on the block. That’s the correct way to do it.