Can a leaking fuel pump gasket cause vacuum leak?

Well I've installed a vacuum gauge on it to see where the vacuum is sitting at idle and it's 17-18 which according to the gauge is in the low side of the good zone. I would like it if it were higher. I don't know what the mileage or the age of the rebuild on this engine is if at all it was ever rebuilt. It's a swap previous owner swapped 225 for a 170. I tried rebuilding the 1962 Holley 1920 that came on the car with a new accelerator pump and all that was in the kit. It still had the same symptom. I tried to check the clearance on the valves the Chrysler way and none were off specs. But I could've still done that wrong because I wasn't totally familiar with the procedure. My mechanic took out the distributor and moved it a notch over and got it to the good running condition it is now. I can't remember what the total timing was but I want to say it was around 30 degrees total timing. I know specs on this year engine is initial 2.5 btc but he said he does by highest vacuum. Which I'll admit the engine runs better than when only I was fooling with it because I can actually drive it now. But eventhough I can still drive it and eventhough it's not a big block high horsepower motor it should still take off when you mash the gas to the floor. What if you were driving it and for some reason had to pass someone or you had to turn in somewhere before a car hits you? It should be able to take off without cutting off, that's almost a safety issue. Does the Carter BBS for this year perform any better than the Holley 1920? I haven't tried it.