Pics and description
The project took lots of trial and error so I'm not sure if these pics are the final version or not, but you will get the idea.
Pic 0044 shows flat stock over the brace from firewall to dash. Glove box will slide back in and clear it whereas if I recall correctly bolt heads might not. There is another one at the back of the heater fastened to that piece of angle also.
Pic 0040 shows the brace and where I moved the air valve.
Pic 0031 shows the basic framework that I used. Didn't have to drill any new holes in the heater but I did have to use an impact screwdriver to get the factory screws out. I either had to shorten the inlet side of the d-box or cut down the cone shaped piece on the heater to get the length of the whole unit that I wanted.
0029 another view of basic framework.
Pic 0034 shows how I used the brackets on the distribution box that would normally mount to the firewall. I connected them with flat stock locked in place on some threaded rod which was in turn locked with nuts and lockwashers to both sides of the basic angle frame in the front and back to make it rigid and parallel.
I had a plumber friend soldier the 90 deg elbows for the inlet ond outlet lines so they aimed upthe direction the hoses came in from.
If you have the welding equip handy you can probably make shorter and neater work of the job. Maybe on my next green machine