I still run mono leaf springs in my 64 Pro Street chevyII fully tubbed and a 8point. and I don't find it to be a draw back of any kind. Heck I even have a 2seater between the tubs. And the rear rails are 29&1/4 apart. With 18gal fuel ceil.
Larry/Twisted6 [oooooo] Adding CFM adds boost God doesn't like ugly.