I was mooching around the web and found an article about a guy's '78 Kawasaki KZ650 rebuild - in it he mentions using a CB400F gear shift to accommodate his rear-sets, as the shift rod splines are the same. So I got thinking (the sound of grinding metal...)
Checked a few part numbers on
http://www.motogrid.com/pages/OemParts?aribrand=HOM, and the selector shaftwas used in a fair few Kwaka's, so logically their spline patterns should also be compatible with the CB400 shifter too. Here's the list -
KZ550 A1-A4 (80-83), C1-C4 (80-83), D1 Gpz (81), F1 Spectre (83), F2 LTD Shaft (84), H1+H2 Gpz (82-3) and M1 LTS Shaft (83)
KZ650 B1-B3 (77-79), C1-C3 Custom (77-79), D1-D2 SR (78-79), E1 LTD (80), F1 (80) and H1-H3 CSR (81-83)
KZ700 A1 (84)
KZ750 B1-B4 (76-79), E1-E3 (80-82), F1 Shaft (83), G1 LTD II (80), H1-H4 LTD (80-83), K1 Belt (83), L3 (83), M1 CSR Twin (82), N1-N2 Spectre (82-83) and R1 Gpz (82)
ZL600 A1-A2 Eliminator (86-87) and B2-B3 (96-97)
ZN700 A1-A2 Shaft (84-85)
ZR550 B1-B4 Zephyr (90-93) and C1-C3 Zephyr (91-93)
ZR750F2 (2000) and H1-H3 ZR-7S (2001-03)
ZX550 A1-A3 Gpz ( 84-86)
ZX600 Ninja (85-97)
ZX750 A1-A3 Gpz (83-85) and
XZ750 E1 + E2 Gpz Turbo (84-85)
Most of these won't do as a straight swap for the CB400F goodies but some will - but the others might come in handy for people building specials / choppers / bobbers absed on the little four.