Do you recall where you got the replacement MC from? Brand/Part Number?
It might be all you need is a brass adapter fitting, but can't say more with out a little more details on the stuff you have.
Pictures would be helpful.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
