Barry, please send the PM... after reading your comment i might reconsider that last statement.
I believe the dogleg Getrag as used in the BMW is a 1:1 final drive over here.
The Getrags are not very easy to find around here, most go the BMW-boys. However there are also some older Opels which use them apparently, like the Opel Monza and Senator 3.0. Will look into that option when i break the original ZF..
For my road car i need to keep an as near to original look as possible from the underside. I have to pass a visual inspection with my car to get a v6 on the papers and it has to look factory made. The Sei diff looks original and the gearbox too, because of the lack of adapters and stuff.
The Sei diffs i have are from 3 different types, 2.5 v6 manual, 2.5 v6 Auto and 2.0 v6 manual. They are supposed to be 3,9:1 / 3,5:1/ 4,3:1. Only the last one i'm sure of, counted the theeth, the others are untouched. Do you know what type of lsd there is in the diffs, plate-style like the 75 or something else?
Drive it like you stole it...