427 tall deck in a '70 C20

[Ol'Blue70]

I recently acquired my grandfather's 1970 Chevy C20. This truck originally came equipped with a 250, 4 speed, and a coil spring rear axle. I am wanting to modify the truck to make it more heavy duty (I'm wanting a truck I can pull a flatbed trailer with). I am planning on swapping out the rear coil springs with leaves.
I have found a good deal on a 427 medium duty truck engine. It comes with a good 4 speed. I know this isn't usually what people use when wanting to re-power these trucks, but I thought this would be a unique, high torque solution to fit my needs.

My question is: what all is required to perform this type of swap? Since these engines weren't offered in pickups, I know I'm going to have to fabricate some motor mounts. How about the clutch linkage? Another option would be to use an automatic. I know where I can get a TH400 for a good price, but I doubt it would bolt directly to the 427?

Thank you in advance for your ideas!