I got smart this w/e and cut the left side off my extra chassis and used it as a jig to get my new heater channel and floor to fender well support fitted up properly to the body.
I also bought an 8mm 1.25 pitch tap and a 10mm (can't remember the pitch) at Car Quest. I have been looking at tool stores for metric taps for awhile and could not find any. I used the taps to chase all the bolt holes on the new heater channels. I also bought a dozen 8mm bolts to use for the jig.This is a view of the left side of my rotted out chassis (yes it is THAT BAD) bolted to the new heater channels.
The inner rear wheel housing comes out of the box with 2 seams that need to be welded up. I was looking for something a little les s thought provoking to work on, so I stitched it up.
This is the whole heater channel and fender well to floor dog leg assembly clamped into place and fitted up. I still have a bit of work to do to get the convertible stiffener buttoned up inside the rocker skin, so these pieces will go on and off another half dozen times before I start welding them up permanently.