75 cc accelerator pump ?????

was at vic hubbard yesterday,was looking thru a percys catalog.they have some interesting items to say the least.one is a 75 cc acc pump kit.the dom i just put on my car has 50 cc pumps as all do, why would you need a 75 cc pump shot ? talk about black smoke off the hit! wouldlike some feedback on the adjust a jet kit they make also.fwiw the dominator idles,accelerates,and runs better than any 4150 carb i have tried on my 360.