My swap options???

[Sport91]

Truck is a 91 4x4 with a 5.7 TBI, turbo 350, and not sure which transfer but i think its a np241.

I want to go to a 6.0 or 5.3 if i find a smoking deal on one. I wouldnt mind keeping the turbo350 (would have it refreshed) but I remember seeing somewhere I would need a certain year engine or I would have to use some sort of spacer???

Also how hard would it be to mate a 4l80e to the np241 in this swap?? Arent they two different shafts 27 and a 32???

[Chevlowrider]

dont worry about the right engine year. I bought a 2002 5.3 and bolted up a th350 to it. the spacer u will need it from a 8.1 truck. i just called my local gm dealer and got one for a 2002 8.1 truck for $27. and the only thing u will run into (i dont have any problems with it, but some people do) is the 5.3 does not have a drilled or tapped hole for a bolt, so youll be missing a bolt. i think its the 3rd bolt up from the right of the tranny. hope this helps, good luck on the swap!