Can a leaking fuel pump gasket cause vacuum leak?

So I've got my 65 Valiant driveable now. Even got it tagged and insured now. Drove it around the neighborhood a few times and it does good. It's the 170 with the Holley 1920 the correct oem number too, less than a year old. I believe I can pretty much drive it wherever and however long I feel ok with. I know the front end is shot though. It starts good, idles good, and drives good. Unless you do full throttle to the floor from a dead stop. I had a mechanic come over and now everything's been gone through, charging system now working properly, timing has been reset, carb adjusted, ignition firing good, points set, fuel pressure is 5psi, new fuel system throughout. That's the only driveability problem now is just full throttle from a dead stop to the floor it will cut off, but it's easy to start up right away so it's not getting flooded. No vacuum leaks apparent at the intake. It's got good 17-18in-hg vacuum at idle. I noticed over by the fuel pump some oil spray but not leaking down from the head gasket or valve cover. So I'm assuming it's from the fuel pump. Could that gasket cause a vacuum leak too causing performance problems but still produce the required 5psi at idle? I can't think of anything else we've not gone through. It's pretty sparse under this hood, no power steering, no a/c. I know it's not a powerhouse but it should not cut out just because you stomp it to the floor from a stop.