Engine leaning out at 3000rpm

It was dyno tuned it ran great for a while then i got an oil leak in the valley pan the 440 source style that goes under the heads so i pulled it out and put a stock valley pan in it with paper gaskets both sides oil leak went away but then i sterted with this lean stumble mess must be an intake leak right? So i messed with the carb an 850 quickfuel for a while jetted it stupid rich to stupid lean no difference when i lay into the throttle it leans out big time runs good on light throttle around here or there borrowed my buddies 750 hp same thing bought this almost 1000 buc custom carb pictures above custom built to my engine specs flows 965cfm thru a 750 base plate awesome carb same thing it has to be in the intake somewhere fuel pressure is good timing locked out at 34 degrees on an msd digital programable 6plus its been plagueing me for a month! Ive had to punk out from 3 callouts so far and it is killing me!