Milling an intake manifold.

Long story short, have the motor apart installing the new camshaft @PRH spec'd out. Bought a new borescope that can twist the head 180* and decided to see what the port match looked like on the intake to head. Well, it's atrocious. The intake manifold is clearly way to high. When I put the motor together last fall with the new heads and intake, I final port matched to the gaskets but was rushing and obviously missed this (first fire up was 9pm the night before the race with a 8hr drive). Without any gaskets between the head and intake the port match is perfect. The gaskets are felpros that are .060 thick. A machinest buddy of mine is trying to cut the flanges on the intake, I told him take .060 off, he did some math and came up with we need to take .042 off. Thought we could set it up in his horizontal mill by bolting one flange down, and then realized it isn't a 90, but 84.
Is there a fixture anyone sells for milling a Mopar small block intake in a horizontal or vertical mill? I know a Bridgeport would be perfect, but I don't have access to one. Any tips or tricks?