I am going to run a toyota cardan shaft in the rear of my Zuki.
I have found a beefed up one ( rebuilt with bigger tubing and new u-joints)
I'm wondering how others have found the extra weight on the t-case shaft and bearings.
Is just running a standard shaft pushing the little case to it's limits?
Should it be ok?

Please help before I spend the coin.

you shouldn't have any problems.  I have been running very heavy driveshafts with double cardan joints for over 10 years in my samurai with no problems at all.   I'm running the dana spicer double cardan joints which are quite a bit bigger than the toyota's.  Go for it !

It's done.   
And thank you for your response.

The difference is unbelievable.

Like it's stock again, but I'm 8.5" over stock.

I'm glad to hear there is some longevity to this swap.