Odd frame question

[Spray-Bomb]

Hey guys, I am currently gathering parts for a new ground up project that Im doing on the cheap

It is a round body (88-98) & I was wondering if anyone has ever put one on a square body frame (73-87)

My reason for asking is that I have a few square body frames laying around, but I dont have a round body frame & I havent been having good luck finding one

Also I have freshly rebuilt square front end

So basically, is the frame width & length (swb) the same ???
I know that body mounts will have to be changed, but is that it ???

Thanks, Matt