IIRC the big push towards the 200R is the case is smaller, necessitating either no cutting or minimal cutting on the floor to replace an Iron case 'Glide in a car orriginally equipped with one.
Sounds like a neat project either way.
I would definetly keep an eye out for lugging when you put an OD in it with the 3.50s. But try it first, never know till you try.
FWIW I'm not sure where it is the cutting is supposed to be necessary, if it's back towards the rear of the trans (where the valve body sticks out a ways on the 700R) the 200 would be advantagous. If it's at the front where it clears the belhousing, might I suggest a '60 Degree' 700R4. It's what they put behind the 60 degree V6s in S-10s and Camaros when so equipped (burdened?). The bell housing is much smaller on those and the internal parts are supposedly the same as the earlier 700Rs (yes somewhat weaker) but are supposed to be able to be upgraded.
If the cutting has to be done in the middle, I figure the advantage goes with the 200R.
Hope that wasn't too confoosing to be usefull.
