Installing a 200R4 would make a huge improvement over your TH350.
A switch pitch TH400 would be OK, but a bit overkill & power robber for you application.
Just think about it, you can run 3:73 (or so) rear gears, accelerate will be a day & night difference, & still knock down the RPM's for freeway cruising & better MPG's.
No driveshaft needed to install a 200R4 & from what I read, reposition your stock cross member.
From what I remember the 2.74 gear sets fro a TH 350 are pricey & more importantly are weak.
I also contemplated that gear set also for my TH 350.
The main reason I did not look further into getting a set was that they are weak & are weaker the a stock gear set.
MBHD
