Drilling a Magnum intake for '73 'J' heads?

I want to run a TQ carb and have found an M1 intake with the spread bore carb flange but the intake to head bolt pattern is for a Magnum engine. Can this intake be drilled for the '73 iron 'J' heads I have? If not, is there a comporable intake that has a square mounting flange that can be opened up to the TQ spread bore size? I know there are adapters for mounting a TQ on a square carb base intake but carb to hood space will already be at a premium so an added spacer is out. Maybe milling the intake & welding on the adapter? I'm not concerned with form so much as function. I'm open to any & all ideas. Thanks.