Donor Truck Question

[67-70c10]

I'm picking up a 67 c10 with a 70 nose. It has no engine or transmission.
I also have found a 72 C20 Longhorn that is rusted almost to the frame. It however, has a 350 4 barrel engine and 4 speed. My question(s), does this truck come with a 4 bolt main block?
I got the block number and its so generic. 3970010-69 to 79, 2 or 4 bolt mains, 185-370 horsepower. These engines were installed in cars, truck and vettes. So as you can see, it could be almost anything. Anyone know a little more about the engines that came in the Longhorns?

Does anyone know which 4 speed transmission(s) came in the Longhorn? I Won't be using it, but maybe could be sold for a small profit!!!

Final question. The Longhorn has power brakes, could this unit be swapped into the 67? I called Autozone and they have 2 differnet part numbers for the different trucks.

Thanks for helping out a newbie!!!

Jim Smith