I'm sorry...I should have responded more clearly at first.
The 2.8 and the 3800 are entirely different blocks and the bellhousings are
not interchangeable.

There are lots of transmissions out there that will fit your car,and I might
suggest you search
www.car-part.com

I have mentioned the 440T4 a number of times on this website, and some of
the variants had their
weak points. Some tended to have short service lives, less than 100,000
miles, or maybe a little more. When rebuilt with the appropriate parts
upgrades, they worked out pretty well.

A proper rebuild should be available for a little over a thousand US.