serious carb issues

well the thing is the carb was setup to my specs regarding power valves, jets, squirters, etc....a company like pro systems did it for me

in regards to tuning, my dad is actually really good at tuning carbs, and we have a ton of holley parts, but this one is really stumping us...we've tried everything, not sure what it is...the old carb was a 650dp that hadnt been run in years, it would idle, but it would die off rev as well...im hoping its not an engine issue and just a carb one