1964-66 C40 454 Swap? School me please.

[MrBeast]

Howdy heavy haulers!

I am currently looking at 3 trucks up in WA, They are c40's/50's.

One has an inline 6 in it, the others a V6.

I am wondering how hard of a swap it is to put a Newer big block in them? I know where I can pick up a 7.4 or 8.1 vortec.

Mainly concerned with bellhousings and motor mounts? I know that GM did some odd stuff back in the day like Chevy being one pattern, and the BOP being slightly different, not sure if the GMC V6 was the same or not?

If anyone has photos of motor mounts I would greatly appreciate them.

What my hope is, is to swap in the engine then put in a hydraboost and independent master cylinder for the clutch.

I had also thought a lot about swapping in an NV4500 if I can source one which would later prep it for a Cummins swap.

Throwing a lot of ideas at the wall right now and seeing what sticks.

The end goal is to wind up with a highway hauler which is also going to mean needing to swap out wheels. The C50 is a 10 lug, the 40's are that odd ball 5 lug?

Not sure if anyone has any insight here, but I do know that split rims are becoming persona non grata many places.

Any info you have to offer here would be greatly appreciated!