Retrofitting 4l80e, couple questions.

[kape]

Hello

My c30 crewcab dually uses two-piece driveshaft. And now i changed Motor(old was 454) and transmission (old was th400)
to 6.5Diesel/4L80e.
Couple of unsolved issues coming up.

Old transmission have yoke with the bolt to the output shaft, it is non slipping model i think, because slipping
happend end of the first drive shaft after the chassic bearing
and 4l80e have slipping yoke.

So i tried to swap the yokes, but old th400 yoke go too far away inside to 4l80e, sealing get bad.
There is somekind rubber after normal oilseal.

So do you have some solution to get this problem solved.

and of course i have to make first driveshaft shorter, but is it not a problem.
i'd like to stay two-piece driveshaft combination.

Many thanks.