I've run into a slight problem with an upper I want to put together. The anti-rotation tabs on the rail I'm planning to use (Diamondhead) won't clear the billet upper (ASA) I have. The upper front portion of the ASA is a little beefy. The rail will work with my ARFCOM billet upper which appears to be a little more svelte.
Can you mill clearance cuts in the ASA upper so it will match up with the Diamondhead rail?