They are virtually the same truck, extended cab long wheelbase the only difference is the 89 is the light 7200 lbs 3/4 ton with 6 lug wheels and 94 is a 3/4 ton with 8 lug wheels. Both are 4x4
I have an 89 Silverado with a 5.7 tbi and a dying 700r4. I have acquired a 94 2500 with a 5.7 and a 4l80e. I would like to know what parts I would have to change to do a swap.