performance issues

7 PSI under load is plenty for any carb. So how are the float levels set? I'd suggest a "wet thread" setting on the secondaries. That is, fuel should be just wetting the bottom of the sight plug threads and dripping down the bowl face. Not a gusher, you should be able to contain it with a folded blue towel. What size needle/seat assemblies are you using? .110 (Holley 6-504) would be reasonable. Once you have verified both of these, and if you still suspect you are lean, increase secondary jets by 4 numbers. This is a massive change. You'll either see a massive difference, or this wasn't your problem.

Make sure you are getting full system voltage to the ignition system.