Would have been nice to find a thread on this swap (I'll keep looking) but I need to make sure plan B is better before I commit to cutting up the K3500 frame for scrap. In hind sight I wish I had not been in such a hurry with my 72 157" RV frame but space was limited and I did not have the 4x4 plan or the 84 that time.
So all I can find that looks useful so far on the 84 frame dimensions is this link.
http://www.chuckschevytruckpages.com/framespecs.html Anyone have better info? I would like to start making comparisons of the 67-72 to 73-87 while I scrap the 84 cab & bed?