'76 350 into an '85 3/4 ton 4x4

[sick472]

I have my old '76 2wd that has a GM 350 crate motor with 70K miles on it and my '85 3/4 ton 4x4 is burning a lot of oil (like a quart every 1000 miles. maybe more). The '76 is almost see-through due to rust. Both are automatics and AC trucks. Neither have any real power to speak of. The '85 has an edelbrock intake and Holley carb with unknown heads and is a 350 ci as well.

My questions...what should I be aware of if I chose to swap the motor from the '76 into the '85? Would it be straight forward or will I have to make mods?

I'd love for this to be a one weekend chore should I pull the trigger.

Thanks in advance!