Have started working on the exhaust and the header.
I've had a pair of stainless steel headers from a 5.0 mustang kicking around f and some non-stainless U-bends from my 221-V8 '70 Mach1 project from many years ago, and finally have been able to use them. Turns out the G10 exhaust opening are almost a perfect match to the 5.0 Fords, but of course nothing is that easy, the mounting holes are way off. So I've cut/welded them into the right positions, and have started working on fabricating the tubing.
I got one of the HF Tig welding guns that hooks up to an Arc welder, so I pulled out my old Arc welder and hooked it up, and what do you know, this ghetto scratch TIG welding works!
I also put my spare low-mileage motor up on the stand and am using it to fab the headers, a lot easier than using the motor in the car, but its there to confirm any fitment.