In this process I learned something interesting. As much of a pain it is to have to clean off several layers of grease and oil that have leaked onto the frame over the 18 years the Jeep was on the road, it is actually good to rebuild a Jeep that has leaked oil it's whole life. The areas with a thick layer of oil and grease were in great shape under all the crap. The areas that were nice and dry had rusted and needed more work to restore. This is one case where you can be happy about a previous owners negligence.
Don't try this at home. Not only is it dangerous, but it don't work...
After I thought I had completed the work on the frame I purchased the fiberglass body and tried to mount it. This quickly brought about the realization that the frame was bent and would need even more work before continuing with the project. I found that the best way to check your frame for straightness is to measure diagonally across it from left front to right rear and right front to left rear. I used the front bumper mounting holes and the rear shock mounts as my points of reference. These measurements should be the same, but mine were off by more than an inch. The picture shows my attempt to correct this my using chains and a ratcheting pull-strap. I could put enough tension on the frame to make everything measure correctly, but as soon as I unhooked the straps the frame flexed back to it's original dimensions. It didn't take me long to decide I had no business trying to fix this myself, so I hauled the frame to a body shop with the correct equipment to straighten frames. A couple weeks and $250 later I had a perfectly straight frame.