other than flex plate, tranny, brake pedal, and shifter, what else do i need to do a swap from 5 spd to auto on my 1990 kick, will driveshafts and crossmember need to be changed, anything else? thanks in advance for the input.

You will also need to swap the radiator as it is used to cool the auto trans or you could just add a seperate auto trans cooler.

If it is a 3 speed auto then the driveshaft is fine but a 4 speed auto has a shorter length front shaft. The 3 speed auto also runs different diff ratios but if you are running bigger rubber then stick with the manual diff ratios as it will be better.

the 4 speeds are also computer controled. if i remember correct, the 3 speed is not.

If you want 4-speed auto, it's supposed to be easy to drop in one from certain Volvo's. The transmission's are made by the same people (read: same bolt patterns, spline counts, dimensions etc), but they built an electronic & non-electronic shifting models.

i read that the 3 speed auto kicks run 4:60 gears and the 5 spd runs 5:12 so swapping from 5 spd to auto is supposed to make it run like it has stock tires though i am running 235/75/r15