I've had heads milled .060. and no fitment issues.. as in I didn't have to do anything to the intake manifold. I do use Fel-Pro 1213s .060 thick intake gasket. But I'm going to switch the next time to the same gasket from Speedmaster for less than half the price. And Summit sells them also... Hear it took 150 bucks to get that much milled off. It would have been significantly last had I just wanted a little bit to clean them up... Also that's buying the Little Harbor Freight Tool to take my Springs and valves out ahead of time.. but did Mark and label and put everything back in the same spot. Also before I put them back together I put a little lapping compound on the seat and on the valve and lapped them... Been cleaned and lubricated everything with a break-in lubricant...
