65 Barracuda engine swap

A "new" Edelbrock intake will not fit your 1965 273 heads. The only Edelbrock intake I can think of that fits the 64-65 heads is the D4B which has been out of production for 40 years.

The best all around "upgrade" for a 273 in an early A-body is a 318. Bolts right in, makes reasonable power and they're cheap. Heck you could probably swap the 273 crank for a stack of 318s.