Might oughta stay on one thing at time, even though I was jumping from one to another at the time. Hell I still am. I must have measured where to put those mount a gazillion times. I scribbled all over that thing before it was all said and done, but as it turned out it was right on the money. Well almost, height was off about 3/16".
Here's some more, hard not to second guess yourself. I had been thinking what I was going to use for mounts. Didn't like the idea of just cutting a window and welding a piece of plate on it. Even though it would have been plenty.
The small part of the clamshell or what ever you want to call it, the part the bolt is supposed to thread into is about 1 3/4" wide, the bigger part that lays between the frame and the beam is about 2" or a little over if I remember right. Hadn't bought the body mount bushings yet so I was going off the old stuff. The hole in the original mount is around 13/16" so you have quite a bit of play. Seemed to me square tubing would be just the ticket, and stout as hell. I had plenty of 2" tubing laying around, but at the time was worried about being off some. I wanted something just a tad bit bigger but all there was to be found was either 2" or 3", 3" just looked huge. 2" would have to do.
Cut the 2 pieces of tube and closed up the end with some 14ga. With the end welded up there might be a chance the body bushing would bottom out on the inside, so it got built a little long. With it being a little long, there was the chance of the clamshell inside edge where it folds over could bottom out on the outer edge of the tube. It was cut back a 1/8 or so to make sure there was plenty of room for error.
Then it got a 3/4" hole drilled in it, those cutters come in handy.
That mark is where I thought it was supposed to stick up above the beam, but it wasn't that big a deal. Both where short the same amount, 3/16".