Thank you Guys for the new Info, very interesting history on this trans, hopefully I will still find the current owner of this car but at the same time nice to know tail shaft was changed to fit a 70 Chevelle LS6 along with the main shaft (Most Likely to fit the different shifter between the Nova and Chevelle and Drive Shaft Yoke IMO), will consider this in pricing the unit lower for the current owner "If I find that person" but all the same for a future sale here in the classifieds in a few weeks or the two guys that PM'd me with interest.

The big output "764" tailhousing and 32 spline mainshaft are worth more $ IMO, the "584" and 27 spline mainshaft are way more availiable.

Good to know, Thanks.
I did some research after you spotted the difference and you were bang on. This Link is amazing for information I found on Google.
A good read for everyone.

https://www.chevydiy.com/muncie-4-sp...ication-guide/