Thanks for your kind words oh great one. :)

It seems that we may have been mistaken. The tailshaft seems too long, but only by a small amount (~1 inch at the most).

This only became apparent as we tried to install it, it was a little tight. However it did go on and this issue only cropped up once we tried to drive it. The problem is that the little cup on the gearbox oil seal is grinding against the "stopper" on the tailshaft, in fact it begain lathing itself quite nicely. The car also shudders from this so we concluded that it's too tight.

My question is, how much free space should be allowed for it to move? It seems we may just have to get the tailshaft shortened.

I find it really dodgy that only this 1 - 2 cm difference needs modification. I'd much rather move the engine forward but I won't.