I’ve said this so many times I want to puke.
Machine the intake face. If you machine the intake face of the head because you think the next intake will fit it you’d be wrong.
The guys telling you that bullshit are not engine builders.
You can buy 4 intake manifolds and measure ALL OF THEM and it’s more likely than not that aren’t all the same.
There are production tolerances.
Machine the intake manifold face the thickness of the gasket on each side and send it.
If your shop can machine a cylinder head they can do the intake.
If they tell you they can’t do it go find another shop.