BBC into 60-66 4x4

[argonaut]

My plans are to put the 402ci big block from a 71 C30 donor truck into my 64 4x4 short wheel base pickup. My pickup currently has a 350 backed by a sm465 trans and rockwell t221 transfer case.

I've read the tread about putting a bbc into a 67-72 4x4 pickup and taken a look at the DIY engine crossmember. Although I cannot figure out why they refer to the 67-72 as a "first gen"

From what I know about 1/2 ton pickups the 64-66 and 67-72 front crossmembers are pretty darn similar. So i'm wondering if this will work in my 64 4x4. Maybe its possible to install and modify the stock bbc crossmember and mounts from the 71 into my 64?

Has anyone here done this before?