guess.
thats about all you can do that i know of. do you have an open air set up like pods or anything other than stock?
After you install your pipe and take it for a test run you should be able to determine how much more fuel it needs at top end.. the main jets are for 75% to 100% throttle so give it all she's got and see if it bogs down. if its a little boggy go up one jet size...if it is super boggy at top end try a couple sizes bigger (hit your choke to make sure its too lean - if it runs better with the choke on that means its too lean)
to make a long answer short - i really DFK, but this works out pretty good and youll wind up with a few extra jets to play with next time your tuning something.
BTW - I am assuming the pipe will require a richer jetting because of a loss of backpressure increasing the intake like i said I D.F.K. but i hope this helps a bit.
quiet people seem intelligent