I have been given a 52 or 53 Gmc Big Boldt. I am waiting for it's delivery so I can get better pics and figure out exactly what it is . But it is the regular Advance Design cab with a fifth wheel. the Frame has been hacked real good so I am going to put it on another frame. A couple of options would be a 63 to 65 1 ton that happen to have a 292 in it. But I will be going with a 261. Another option is a 1960 C-60. Which I think has a 261. The wasps ran me off before I could get a better look. Anyone try swaps such as these or any comments? Thanks.