The 1 3/4 headers should be fine for all but the wildest applications.
I have 2 " and mine rattle off the pass side of the engine bay and one torsion bar (aftermarket 1" bars).
Not bad but it does hit.
I will take 16hp and 22tq every day of the week. And that is just peak. I would imagine gains would be larger in most cases across the curve and hold on longer after peak as well.
Beautiful and ambitious project. Is it a completed running and driving car ?
If more work is needed what would that be?
More details on transmission,rear end,etc.
I am not in the market but I bet it would be a handful and surprise many a fellow.
I have a 440 in my 72 Duster with manual steering and I can vouch for the 2" Tti being tight. Mine rattle of the pass fender and a litt;e off of the PST 1.03 torsion bars.
Depending on the gear ratio and converter I would lean towards a dual plane most likely. Lowish compression and a larger cam = dual plane for low end torque in my book 90% of the time.
Some C bodies run them that way and exit at the corner of the bumper. Pretty sure the wagons did that so maybe b body wagons also.
There are some listed like that on the Tti website.
I want to run it that way on my 72 Newport but don't want to pay what they want for tailpipes. Especially being...
No pics survived. 1981 I bought a 73 blue Charger with white vinyl top and white bucket seat interior with console. 400 / 727/ 3.23 surefrip 8.75 rear end. That car survived 2 years of me. No small feat. I would love to recreate it if I could afford it.
Closest internet pic I could find.
I tend to err on the side of caution these days. If it is a street car with the occasional trip to the track I would run 3.55 gears. With your short tires it will be more like 3.73.
Even with taller tires it will pull fine and the converter will put it on the cam.
Remember it is a light car and...