Cab Mounts
You don't need to pull the cab off...just up. I had the bed off, so I just laid the back of the cab down on the frame, windshield pointing in the air. However, since you are probably leaving all of your body parts on, just lifting the cab up enough to get the mount off will be fine. It will be harder since everything will be in the way, but you can do it. A couple of bumper jacks and 2x4's will lift the cab once everything is unhooked. Just do one side at a time.
Just take your time. I replaced the floor at the same time as the mounts and that took a while to get everything lined back up perfectly. Just replacing the mounts won't be so bad. If the floor is rusty, I would fix/replace it at the same time. Measure twice, weld once, then again, and again until you get it all welded
.Check for frame rot as well. The old rubber bushing had taken in water and rusted my frame, so that had to be patched as well. It would also be a perfect time to install new bushings all the way around.
Just have some perspective on how well you need this to turn out before you start. I have an old F250 that I patched the mounts on by just welding some scrap pieces of metal in 20 years ago, and they lasted for the life of the truck -- they weren't pretty but they served the purpose.



