ign. timing 340 vs. 416

well one of the reasons i posted this was, i had to put a bigger shooter noozle on the secondary side of my 750 hp carb. after i added the 1 inch open spacer, it was a 28 nozzle in the seconday side - changed it to a 35or 37nozzle , with34 deg .timming,that got rid of the hesitation at wot, i just added 3 inch ex. vs. my 2/12 , now i have that momentary hesitation again, im thinking itsa little of both , needs a little more timming, and a little bigger primary size squirter.