Engine milling maths

OK: How you show the bolts is how you want it to be when you loose fit the bolts, with the bolts at the bottom edges of the intake holes. The intake moves straight down as it crushes the gaskets, and the intake holes will move so that they become better centered on the head holes and bolts.

BTW, do you have the thinner intake gaskets on there?

With head milling, the bolts will be harder to line up (tighter to the bottom of the intake holes) and if my wee brain is working the geometry right today, milling the intake face will correct that particular issue of the bolts and bottoms of the intake hole interfering. Milling the head's intake face will also fix it, as the vertical drop in the level of the intake holes gains you clearance. Either way is like putting in a thinner intake gasket. I thought that the intake face angles have been set up by design to allow that to happen once the head is milled on the main face and this particular problem shows up.

What you don't want is for the bolts to line up at the TOP of the intake holes when loose fitted. If so, then the bolts have to bend or tweak the holes in the heads as things get torqued, and face milling on either side will make this worse.... again, if my brain is working the geometry right. The only solution once you get there it to use thicker intake gaskets.

BTW, having flat washers under the bolt heads is important to allow the movement of the intake relative to the bolt heads as things are torqued, especially with an aluminum intake. Hardened SAE (narrow) flat washers are best IMHO.

FWIW, someone here told the story in the past of of having someone else standing on the top of the intake to crush things enough to get the bolts started in a case like this LOL