Not in my experience.
'73 Duster with rebuilt stock 225. The engine was set up with cast iron Super Six manifold along with a Autolite 2100. I changed out the Super Six for an Offenhauser with the same carburator.
'65 Dart, mildly built 225. changed over to the Clifford with the same carburator.I gained 2 tenths on the track and there was a noticable change in the butt-o-meter with better response through out the entire rpm range. Conclusion, the Clifford is a better over all manifold.
I also drive my Dart daily. So i have extensive experience with this combo.
The 500 AVS is a very capable carburator.
It is not a crappy 40 year old remanufactured piece of junk, with a worn out throttle shafts.
