nope. 2wd was ifs. if you got a 72 body it needs a 72 or older frame....73-86 were the same but i don't know about 72. you could always try for a 73 or newer
Well the best thing to use would be a pre-73 4wd frame for a SWB or LWB... The K5s are shorter then a pickup, and 73-87 uses a different frame. A 4wd van frame would be hard to find...
You can swap the front crossmember, rad support bushing mount, etc. & more or less, bolt on 4wd front suspension. Knocking the rear bushing carrier for the front leafs is pretty easy as well.
If you have a coil trailing arm rear, do a axle flip.....if you have leafs, you're golden.