Hi. I'm restoring my 1989 K100RS, which has been laid up for 8 years. The gearbox case has lost 1 of the 2 lugs that support the clutch operating arm. OK I confess. Yes, I did learn a valuable lesson, now burned into my psyche: "Never neglect heat. If you lack the means, get them."

I've got a potential replacement case of undefined age but clearly earlier: it lacks the undrilled paralever supports and the drain plug is towards the engine end of the box not the rear as on the original. I want to use the components from the orginal box because they look generally in better condition and I know the box was OK. I'll replace all bearings and seals and shim for endfloat as instructed.
My question is whether I can be completely confident that the earlier box will be identical other than in the above respects. Thanks very much! Chris

The only real difference is that the gearboxes that came with a 16v engine had a slightly taller 5th gear. The large helical cut gear in the intermediate shaft had 29 teeth as against 30 teeth on the earlier type. Some were black and some bare alloy but there was no other changes right through to the introduction of the six speed on the K1200s

Thanks Rick. That’s very helpful. The later box is from 8 valve. I’ll go with later components in older box. Cheers, Chris