Are there differences in the 2 speed for 12,8,6?

Quite a number of years ago I purchased a two speed axle advertised as for an 8-cyl. Several years ago I was talking to Glenn Pray, and he asked me to bring him a paper tracing of the housing ends and overall length and a few other dimensions. Once he saw all of that he said, "Well that is going to be a bit of a problem. That is a 12-cyl two speed." Needless to say it has not been installed in the 8-cyl car it was bought for. Guess they are quite a bit different.

Thanks Curt,

I'm having a flashback to our recent conversation at Hershey on this subject and my head is spinning. I think the short answer is that there are lots of differences, even when the external unit looks identical and dis-assembly is the only way to see what rear end you truly have.

AJ, I do not know about pre 1934 cars and 12 cyl two speeds. I can say that the two speed offered in 1934 carried into mid 1935, at that time there was a running change internally that most of the parts do not interchange. That differential carried through to the end with only changes in ratios. The six cylinder is exactly the same as the eight with the exception of the axel half shafts and the backing plates.

My dad and I were wondering about this today. What are the differences, if any, between the early & later 2 speeds, or 12 vs 8 vs 6?