07 20" wheels on 72?

[snakeplisken]

I would like to put a set of the new 20" wheels off a Tahoe (6 x 5.5") on my 72 Chevy 1/2ton short bed. Has anyone done this or know what it would take to do it? The truck is an all stock (2wd) 72 Super Cheyenne that was restored before I purchased it. Only thing missing is the factory radio and wheels. I think it would look nice to add a little new school factory look to it but not sure if it is possible.
This is my first time so be easy on me.