splitty rear bars?

so what the deal with cut-outs in rear bumper bars.
am told that their for exhaust but if there not there originaly does that mean when you fit extractors you need to cut out a section of the bar?
if I'm going to put an original muffler on I shouldn't need the cut-outs.....right?
can I put a bug muffler on there so I can put my Zoom tube on for something tricky?
Rob

Extractors will fit without cut outs. A bug muffler needs cut outs to clear the tail pipes and a zoom tube would need major chopping.
Nik

ok so now I'm stumped,what sort of muffler came out on a 66 splitty?

A larger rear can and a long small diameter pipe exiting way out to the left,under the bumper.