I put a 53 mm throttle body on top of my M1 last year and was surprised how well it works. I expected to lose a bit of power down low, but I think it's actually better.
Nice! Thats for that Allpar write up that helped a lot! Well done!
As I looked at that intake before, it did certainly seem to have longer runners. But never held it in my hands. I can say the plenum area also looks smaller but did t know by how much. Interestingly the writer put an approximate CID limit on it at 370 cubes. I’ll assume that is the guess limit to the manifold “As Cast.”