I used 2 driverside 77 Nova exhaust manifolds.They are a lot more common and,,,,,cheaper.I paid $5.00 each for them.I had to use 2 driverside ones because I have my small block bolted in with 55-57 pass car mounts (a four point mounting system, using the cross member at the front of the bell housing.The 77 passenger exhaust manifold dumps at a 45 degree angle into my mount so I used 2 driverside ones, doing that they look like 55-56 , 265 exhaust manifolds.The left side dumps at the back and the right side dumps at the front like a 55-56 chevy V8 now.Both sides clear the frame, but I had to move my steering box out 1 3/4 inch out.
Lothar