Things here slowed down just a bit. My daughter was getting ready to graduate (Valedictorian!) and we had friends and family coming in for the event.
Things are starting to pick back up again and I did cut the cab mount ears from the Dodge frame for reuse. Once I had them all cut off, I used my 2" square tube and the 1x2 to mock the cab mounts into place.
One of the issues I encountered was a conflict between the rear cab mounts and the front crossmember that supports the fuel tank. In order to repurpose the factory brackets from the Dodge frame, it looked like I would need to modify the crossmember. I took another look after anticipating notching the frame in that spot, and found a better solution.
The factory Dodge insulator is a two piece unit that has steel backs top and bottom. The upper half has a stepped down extension that sits through the frame mount and seats into a rubber donut backed by a large steel washer that cups it all together. The mounting bolt runs through the middle to pull it all together. The problem I ran in to was the position of the mount and insulator in relation to the frame of the truck. The width of the rear mounts on the cab is just about 2" wider than the frame of the Dodge. The insulators need an extra 1/2" spacing in to the frame due to their circumference. Also the thickness of the lower portion would require a notch about 1/2" deep.
All of this puts the bracket for the insulator right over the two rear-most bolts that hold the crossmember for the fuel tank to the frame. Instead of cutting the frame and crossmember to accomodate the cab mount, I trimmed the cab mount back on the front edge to allow the crossmember to slid into place and be bolted up.
This still leaves the issue of the lower washer interfereing with the frame. Instead of notching and boxing the frame in that area, I notched the steel washer. By trimming off 1/2" and making a flat spot on one side, The washer and the lower half of the insulator fit in place.
When everything is torqued down, the washer should have no contact with the frame at all. Normally the washer has the lower part of the bushing glued to it, but I pulled the bushing off to cut and fit, but the bushing will be back in place for assembly.
I tacked in the rear cab mounts on the back side for now. I still need to make gussets to extend down to the frame front and back for structural support, but that won't be until I am sure it is all squared up and I get some more 3/16" plate steel.
The front cab mounts were about the right width off the Dodge frame, but were too far forward and too low to accomodate the Chevy cab. Once cut from the frame and mocked up with the bushings, the lower edge of the mount was now level with the top of the frame rail, though hanging in space. In order to tack things in place, I added some 1/8" plate I had on hand. Again, once everything is finally located, I will make gussets to extend the mounts down to the frame, top and side, for structural support.
This morning I went out to recheck everything and found a 1/2" variation on the right side of the frame, between the cab mounts. It was getting ready to rain and I had to go in to work a few hours later, so for now, I am at a stopping place until I find and fix the error and can finshing welding in the cab mounts. As best as I could tell, the right front cab mount is about 1/2" too far forward. Thank goodness I only tacked them all in place.
-Joe