4L80E Tailshaft abomination???

[88Ironduke]

All,

Hoping the transmission god chime in here. I am collecting everything for a 5.3 LM7 and a 4L80E reman unit from an 03' Express van going into my 72' C10. The transmission has the typical fixed out yoke so after a quick inspection I order a counter bored yoke assembly to make the slip conversion possible.

New slip yoke from Denny's Drive shaft shop out of New York arrives in the mail. Its a new Sonnax unit counterbored for my application. Here is the rub, it seems I have found the unicorn in the Herd. This particular transmission has an output shaft housing that can also receive an external trans mounted E-brake if the vehicle is equipped. It has a roller bearing installed instead of the bronze bushing typically found. The new slip yoke fits the output shaft as advertised. I talked to the vendor and the slip yoke is correct for my application but the tail shaft is wrong.

Did the 4L80E receive different tail shafts thru the years or are they interchangeable, etc? I know the Turbo 400 shares allot of common parts with the 4L80E, might this be one of them? Need some help here.

Thanks
Paul