I doubt you'll see any difference going from a 52 to a 51 jet. A 35 nozzel is pretty big, though.
Top end would be more on the spring selection you have for the secondary. The primaries can only do so much. I think that's where you need to play next. For me the second weakest spring is the one that works best. Secondary spring kits are cheap. If you really want to play around with it Holley makes a quick change kit for the secondary spring that you might find useful.
Sounds like you have the primaries sorted out. Time to go and play with the secondaries.
Well, uh, I was going to try the 32 nozzle first, but after dropping the gasket, nozzle, and screw down into the throat and ever so gingerly removing the carburetor, I did the work on the bench. Since the hesitation was still sizeable with the 31, it seemed unlikely that 32 would do the job so went straight to the next size up, 35. I didn't want to take the carb off again! You'll note that I have the high compression engine and larger intake valves with porting done on the head (no lumps though). I think I have the same CAM as your new one. But I think the combo leads to bigger nozzle.
Just watched a youtube video on changing the secondary spring kit. Looks like I can do it easy without removing the carb and with tiny risk that I shoot the spring into the carburetor throat. :-)
