H1B has different baffle than H1/A with smaller opening.


H1/A and H1B are two piece.  Later years are one piece and not interchangeable with early.
Baffle for H1B is similar to late baffle shown.

Rick, I have a question on the late H1 exhaust systems (73-76).
I noticed each year is slightly different.

H1d - has front mounting tabs, solid rear mounts, center pipe has extra rear tab that bolts to the right pipe. Front mounting flanges are smooth & have the small holes. No stamped markings.


H1e - front mounts eliminated, rear mounts have rubber inserts. Flanges have large holes & have a rough finish.
Stamped "KHI 500 H1"


H1f - stamped "KHI 500 H1 DGM 13127S" (this same number appers on the air cleaner & snorkle)


KH500 - stamped "76 KHI 500 H1" has an inside coating to reduce noise.


Then there are 74-76 style pipes with no stamped markings. I assume they are replacement pipes.

Is this info correct ?

That's about the score on it Ed, you will also notice that most of the H1d pipes have a thinner flange where they enter the cylinder - - But I just checked 2 NOS H1d Right pipes and one has a mainstand buffer locator and the other doesn't.