1986 Sierra motor/tranny swap

[1helluva86]

hey,
I got a 1986 sierra short bed 2wd with a 305/700r4 combo from the factory. I want to swap a built 350 and th350 tranny in its place. Does anyone one how difficult this will be with the different transmission. I know the motors are a direct swap, but was wondering is my best bet to get the drive shaft lengthend for the th350, get a longer tail shaft, or just put a higher stall converter on the 700r4. I need a 2600 stall to go with the engine combo.
appreciate the help.