I am trying to chase down the cause of coolant in my oil. I have a brand new engine, heads, and intake. The heads had shipping damage and had to be milled .021 (if I remember correctly) to take out a nick. If you mill the heads do you have to mill the intake to get a correct angle to seal of the intake to heads?

 

If the heads are straight milled, then the intake flange angle does not change. Only the "width" across the top of the engine as measured between 2 fixed points on the heads changes. Specifically, the ports and bolt holes all move down and in.

For .021" of milling, you probably wouldn't have to fool with the intake..... unless they had already been milled before you got them. ALOT.

I doubt that's your problem. A leaky intake gasket could be, but not likely a result of milling the heads.

 

You should always have the intake taken into the shop that mills down your heads to have them check it out. It can make a difference. If the bolt holes are off a bit, it may not seat properly no matter how much you torque it down..