[ngoma]

Which gasket? The thin square one? Usually those can be carefully cleaned up and reused.

Why do you say it can't be fuel supply or IP issue?

Could you possibly have left a rag or paper towel in the intake or exhaust plumbing?

Did you open up the intake manifold extension piece that connects to the turbo outlet hose? What did you seal it with?

What story does the smoke (any?) tell? Color, amount, when?

Different nozzles are always a sexy temptation but theoretically the stock have plenty of extra capacity for overfueling before they become a limiting factor in power generation. Looks like you have the sequence wrong. Mod the IP first, then the nozzles as necessary. Or at the same time, like if you send the IP to Giles, and tell him which nozzles you plan to run, along with any other mods.