[ultraflo]

What nitrous system are you running? A bog and puff of black smoke sounds like an over rich condition... you need to make getting a fuel pressure gauge a priority, along with an adj. regulator. And which in-tank pump are you running? What HP jetting do you have the nitrous system set-up for, is your jetting correct? (double check to be sure)

I've been in numerous mustangs with loud fuel pumps, that souldn't be a big deal, run a hobbs switch (fuel press. safety switch) if you're worried about the pump... or get a bigger pump (depending on what you run now).

The Magnaflow pump I run is all you can hear when the car has mufflers on it.... loudest damn fuel pump I've ever heard, and it works great.

BTW, what plugs are you running and what are they gapped at?