Does anyone happen to know how far apart the cab mounts need to be for the front of the cab? I have a pair of replacements that need to be spot welded on, but I'd like to make sure I'm putting them right where they should be.

I believe the width, on center, is 46" from one front frame cab mount to the other. It looks like there's a small amount of wiggle room in the cab mount itself to get the bolt and bushing lined up properly.

 

Best thing to do would be to set the cab on the frame, (with the front of the cab supported) and then slip in the mounts and make sure they line up with the frame perch holes, and then weld them in. Maybe do a few tacks and raise up the cab to do the final welding...

 

The guy doing the welding wound up measuring from the outside of the cab to a point in the middle of the floor pan (on both sides). The gap in the middle from his measurement was 46 inches, which should fit the perch holes. He also measured diagonally to the rear cab mounts, so by math and measurement, it should be good. I'll keep you posted and thanks!

 

Yeah, I was also thinking of that method, and it's probably what I would do, if left to my own tooling and equipment. He could also build a wooden jig out of some two by fours, and then tailor it to fit the frame and mounts. Then you can carry the jig over to the cab, and set up the mounts according to the jig. One could get it dead-nuts that way, but I still like the bullet-proof fool-proofness of having the cab over the frame.

One would also want to ensure that the cab mounts are level with one and other.

 

The wooden jig is a good idea! I wound up dropping the cab on the frame with a hoist and managed to line it up perfectly. Thanks again!