milling 360 heads

Mill'em, don't be scared, you'll only need to really change PR length and cut intakes if go a lot.

340/360=it's .0048 per 1cc and .0095 off the intake face of the head or intake itself for every .0048 of the head....... and .0144 off the bottom of the intake for every .0095 off the intake face weather it be intake face of the head or the intake manifold.

I milled .040 of 1 and .020 off the other for my 410, better check'em!

FWIW 273/318 is a different formula-smaller chamber to work with.