It has come to my attention that my left front cab support is rusting out. Noticed a rusted hole a little while back that is worse than I first thought and will need replacement soon. Anyone here dealt with this before? I can find replacement mounts for about 200 bucks a pair and figure I can manage the replacement for now. Just not sure whether the floor is rotted also.

 

On top of that, what wiring harness is run thru the cab support? I am seeing a small, 1/4" or so loom inside of the cab mount.

Not sure on wiring, what I have done in passed on cab support on ld chevy if there isn't much there to weld to or you don't feel like doing lots of work right now. I've cut the existing one out with whatever means and used a 4x6 block instead,then drill a hole all the way through the floor and shove a long bolt through wood and mount. Not the prettiest but works. 

Other than that all you can do is cut grind weld crape etc, till you like it. I'm not looking forward to doing mine someday as its getting worse every year. I need rockers, cable corners, fenders, probably cab mounts, new bed etc. I thought about letting it go for as long as I can and then swap the cab and maybe build my own bed. Maybe less work in long run. Good luck ether way.