Can I use exhaust system band clamps?
 

I’m replacing a center section of rusted straight exhaust pipe in a 560 stretch limo. I cut out the rusted pipe (which was originally welded in crudely by the limo builder) and want to know if I can use stainless steel band clamps to attach the replacement pipe if the ends are the same diameter and butt together. Are these band clamps strong enough hold two pipes end to end or must I get the ends of the replacement pipe expanded to slide over the existing pipe and use regular muffler clamps ? I want to be able to easily take apart the exhaust the next time I need to replace a muffler or pipe (or when I replace a transmission) and regular muffler clamps just crush the pipes.

The pipes should either be butt welded together or a new section should be made at an exhaust shop with expanded ends to slip over the old sections and then clamped.

Get the pipe expanded & use "full circle " clamps ( they will not crush your pipe ).
Nothing is going to hold 2 pipes butted together! Especially on a stretch limo.
Another optoin would be to have matching flanges welded on both pipes, which would enable you to just unbolt it if necessary. ;)