A friend of mine has a '69 Stang. He took off the old Holley and bought a Qjet and the engine don't like it. He is now buying a new Holley. I think stories like this abound on both sides, and products can be good or not so good ......

As for me it's Holley or Demon ..................

BTW before you change carbs, and I agree your 750 is too big, make sure the idle system is set correctly. Are the plates within the idle circuit transition slots when at idle? Does she respond when you tweak the mixture screws? Running way rich? Power valve stuck/blown due to backfiring? The idle circuit can have a dramatic effect on how she responds to stabbing ...........

Regards, Kitz