  #1) 18300-028-000 - Very Early 2 piece, 2 tab on top, 45 degree header #2) 18300-028-010 - Early 2 piece, stud mount to frame + forward tab mount to crankcase, 45 degree header (*the magic switch from part 18200-028-000 45-degree header to 18200-028-010 90-degree happens here at frame serial number 527510) #3) 18300-028-010 - Late 2 piece, stud mount to frame + forward tab mount to crankcase, 90 degree header #4) 18300-028-020 - Late 1 piece, 1 stud mount, 90 degree header #5) 18300-028-670 - Very late, 1 piece, 2 stud mount, 90 degree header |