If your running manual steering, you can use Ram truck or jeep stock manifolds for the 5.2-5.9 with minor modifications, they have a 1 7/8 exit port, I'm sure they flow better than 273 manifolds. look at other threads for more info. You can also look for some 2 1/8 exit port ones just more modification needed for early A body.
I'm doing a mockup a 5.9 in my 64 Dart now, so far everything fits except steering column and shaft, I have the parts now to upgrade the column and shaft, I just need to go slow due to the body not wanting to do what the brain says.
