for those of you in the know, the series one gearbox uses shifter forks when the others use roll pins, thus increasing the length of the shifter housing about 4 inches toward the rear of the car. in order to put any other tranny in a seires one, you must cut the tranny tunnel (not good) or buy an adapter. my question is, who makes these adapters? i've seen one once, but i can't seem to find it anymore! any help? thanks guys

 

I've never seen an adapter for this.

 

The S5 and S6 boxes lines up pretty good in the S1 tunnel when cutting the shifter tower and bolting the rear holes to the mounts in the front. You would have to cut the linkage 103mm and drill a new hole. I have done it on my '80.