woop'n the 5
So which 580 ?
My expereince with that vintage suzuki motor and suzuki engines in general, pipes don't do much, more noise, move the power band around and mostly up.
Suzuki has traditionally had very mild porting and cat built pretty good pipes so not many pipe manufactures have feasted on cat bussiness. The upside is on the older single exhaust port 580 like the ext.....a god port job can really wake them up...........sort of a lost art now. But can't hurt much, wider exhaust port. the later 3 exhaust port ZR engines didn't respond as well to port work, but did quite well with the big bore kit, basiclly the 700 pistons.
The old twins pipes give you one nice upper mid range punch and its a trick to make the jetting work right there and capture that little poof of power.
For most the twins will be a pain in the butt and any gain will be off set by constant jetting attention especially if you ride elevations. If its an efi sled, run it at about 8250 and show it no mercy until the cases and crank finally cave in.