4.0 v 2.9 trans difference ?

[sofa king shifty]

just wondering the difference between an a4ld built for a 4.0 and one built for 2.9. heres the deal, im getting a trans off a 4.0 for my 2.9. what exactly needs to be changed? i know theres a valve in the vb thats either high ratio (for 4.0) and low ratio(for 3.0 0r lower) this shouldnt be an issue since im using my rebuilt vb off the 2-9. i know the vac mod is different, but is there anything else i dont know of? i assume changing bellhousing is nec. what else should i change?

 

[sofa king shifty]

ok, found out the bellhousing is the same. would it be a problem to use my rebuilt vb from my 2.9?

 

[BrooklynBay]

The check ball configuration is different for each engine, and the torque converter has to have the correct RPM range.

 

[sofa king shifty]

so using my 2.9 vb would solve the checkball issue? and likewise for the tq?

 

[sofa king shifty]

also, when i rebuilt the vb using the transgo kit it said nothing about engine size as far as checkball location. i rebuilt as directed.

 

[BrooklynBay]

It's not a good idea to reuse an old torque converter.