I have cut and trimmed, and trimmed and measured until I dream about this at night. Prior to changing the blade in the saws all, a trial fit to finalize the cutting is mandatory. Before one proceeds with a project like this, its critical to have a very good plan regarding the handling of the flexible body.
Since my concept was to roll the chassis under the body and carefully lower the body to the chassis while observing any "issues" the first anxiety driven step was the lift!
I snatched an older than dirt (that's me!!) 500 lb cable pallet jack on Craigslist for the rear and used the engine hoist on the front. The rear on the body is not hard to handle but the front is more than I can lift. I'm the Lone Ranger on this and am not interested in a tragedy.
I did not want to cut up my steel sawhorses but this was too high. Will whack'em of for the next lift. Notice the bow in my carefully engineered laminated support beam???, the front is a little heavy.
Give me the saws all, a new blade, and the MIG and onward................