well then , the BB was actually easier to do than the SB. I had mine on my 4 poster and it was on the ground ! make sure its central on the ramps ( my starter motor was off on this one as well ) and they slide in from underneath .
When i got it , it had the hooker straight through muffler tube which is a hole about 1 5/8 ? (from memory ) sounded OK (it went over the pits with them !!!) but kinda restrictive so i tried to pull them out but they were stuck so i made new side pipes and put some sweet thunder 2.5 inch (hole-straight through) in them , amazing differance , really made a differance to performance but WAY TO NOISY for the fun police .
So i put these sound reducing cone thingees on the front
i also drilled about a thousand holes in the muffler tube and wrapped it with steel wool and fibreglass packing and forced it all back in the pipe and it sounded pretty good.
i welded a nut(s) to the muffler end cone to bolt the perforated cone to it, i added a spacer between the two cones so its not so restrictive as well
so to answer your question its too loud (for me anyway)to run open pipes as it hurts my ears after a few minutes