Exhaust system difference, 65 vs 66?

[SandDiesel]

How different is the underside of a 2 door, hard top, Belvedere II going from 65 to 66? Would an exhaust system for a 66 383 car be very close to fitting the underside dimensions of my 65 383 in other words? Always on a budget and trying to make something work.

 

[64BEL]

My educated guess is they should be very similar if not the same. But that's not from first hand knowlege - just my guess. Surely someone else will know more definitely.