Bill, when I got my 64 burb it had mounts & frame brackets from 73-87 truck. This gives you the clamshell mounts that won't come apart if they wear out. It can easily be done-need to use a spacer on top as you have noted. I have seen a stack of washers or better, a piece of 1/4" or so plate. Only thing if you are using the ram's horns is keep an eye on crossmember clearance, with the engine moved forward it can be tight w/straight down dumps- on the 67-72's some have angled back dumps. Brian