[Bob Kontak]

Just a data point...........

I put the Fabspeed Euro pre muffler on my 81 SC. It's a fancy name for a cat bypass. Also ran the Bursch (pretty sure it was Bursch) cat bypass test pipe for years. Just a collector with an empty tube and an O2 bung.

Neither made any "write home about" difference noise wise.

I did buy and gut a fairly pristine 3.2 muffler and throw it on. That was loud and frankly the SC did not have the stones to make it sound rich at higher RPM's. It sounded boy racer above 5,000 RPM's.

It sounded great at low RPM's, really great, but there was only minor baffling in the Fabspeed. Otherwise, open tubes.

I say try the Monty muffler without messing with cat first.