I don’t know how much different the early a bodies are, but I was able to(barely) pie cut a 4” downpipe that snakes between the trans and torsion bar on my duster. First time fabricator and welder so it’s not pretty.
Also, I found that there is ample space between the dash and firewall for an air water intercooler(1200hp frozenboost). But once again, different cars.
I’ve considered that route with an intercooler. There’s quiet a bit of room between the glovebox door and firewall on this 65. Would love to see pics of your work. Do you have a build thread?