Had a monojet on mine(235), then put on the correct rochesterB on. It is exactly as you say mid and top end went away, I'd dare sy mono has to be a third bigger in cfm. I know the stock oil bath air cleaner is too small to fit it. It is just a bigger animal.

Last edited by sstock; 04/20/2013 11:13 AM.

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration