Good question regarding what is next. My big plan given the approaching cold weather is to get a solution worked out for the exhaust plumbing. This will involve making cutouts in the top of the frame and possibly the bottom. If I can solve this puzzle, I will then take the engine apart over the winter in my basement and do whatever is necessary to strengthen the frame where the cut outs are made.
The first photo shows a historic photo taken from this website showing the installation with the factory cast iron manifold - which looks quite well designed for a reasonable level of performance but not the fire breathing level that many cars have now. Unfortunately, there are no photos that I could find that showed the installation from underneath.
The next photo show a typical bunch of snakes fabricated manifold which is a nice but noisy and expensive solution.
The last photo shows where I am now with the cut out in the top flange. The factory down pipe is not a possible installation without some trimming of the lower flange as far as I can see.
So, in the next few days , weather permitting, I will lift the engine out, install the factory pipe and get a better idea of where it runs, . More photos to follow!
Thanks in advance for any suggestions
Grant