Pipes: Dr. Q, Jerry hall, Aaen, CT Racing, Kenny Roberts To name a few. Some builders want the bike there to make sure pipe fits bike correctly. I have a Dr. Q, have had a hand coned Q and CT hybrid pipe. All of my pipes have fitted without my bike needing to be there. Guess I have been lucky or  blessed. Others I know needed the bike there.

If you need/want another 250 motor my friend has n 86 lt250 new bottom end needs top end. I have a ported 88 lt250 motor complete.
500s now reside in 250 frames and looks like one more to come.
Oh prices on hybrid pipes somewhere around 400 or 500 to 1000 that I am aware of. Mild to wild performance.