[RWebb]

Great - glad you could find it

unfortunately I don't recall the thickness - BUT it was for a typ 911 trans. and a 1973.5 body, so you'd need to have measured for your car anyway.

I did not need to mill that piece of steel down any - I just used a commonly available thickness, cut it to size; added threads & had it powder coated.

start with 1/2 inch and see if that is about right - the coupler will obviate the need for an exact match (and I don't have my shaft exactly in the center... anyway)