Frame for my 66gmc

[66gmcman]

I have a 66 gmc 1/2 ton that i am about to work on. At the present plans are to remove the body and do the rust repair to the cab and reassemble it to drivable condition with new rebuilt 5.3L. My frame needs a complete over haul as well. Question is. I have a friend who says he found me a 1973 chevy frame completely restored with all new parts for next to nothing. How would the frame mount to my 66 body? Any modifications to be made. Figure would be cheaper than redoing my original frame and a bit of an updated frame work. Just want a good running patina looking truck. Keep the rest of the body as is as the rest of the body is fairly straight but a fair bit of rust.