[Chrislong]

It shouldn't do Carl mate, the 4 gear has a step in the lugs (by 0.03") but the new bulkhead is 0.03" thicker, so the gearbox should mount flat. Its only when you mix up new/old parts when the shimmage needs to be different front to rear to compensate.... easy tho.

I use 0.06" shims front and rear.