I was thinking of selling my 42lb injectors from the maggie and the stock maggie boost a pump and moving up to larger injectors and upgraded boost a pump. With better pump and larger injectors and fresh tune could I see some noticable gains?

Changing out the BAP will most likely not net you anything.

IF, and only IF, your duty cycle is abnormally high, and you are running out of fuel, then yes, you can pick up some power. Not alot, but by default, you could pick up a tad.

Where you WILL gain, is safety. If your running out of injector, some 60's will give you the safety margin you ned.

Honestly, I think ANY S/C comapny that offers 42's with their system is cheaping out. 42's are NOT enough for aboosted C5.:bs:

Yes, Yes, I know KB does it as well. That is why I normally try to talk the customer out of keeping that in their order..:ack2:
I was thinking of selling my 42lb injectors from the maggie and the stock maggie boost a pump and moving up to larger injectors and upgraded boost a pump. With better pump and larger injectors and fresh tune could I see some noticable gains?

All depends on your HP level... 42's will go safely into the mid 500's RWHP but above that you are stretching them very thin. Especially on a boosted app like Jeff was referencing.