Driveshaft will need to be shortened about 3" if the TH350 has 6" Tailhousing..
Need the TV Cable & Bracketry, TC Lockup kit etc.. lots of Info on here.
The 700R4 has a lower 3.06 1st gear compared to the TH350's 2.52 1st. So that will help launch/takeoff.
The 700R4's 1st to 2nd gear shift has a big drop tho' 3.06 to 1.62 ratio.
.70 4th/OD will drop the 3.23 gear down to 2.26 ratio.