I did the upgrade on mine about a year ago, here is a pic of the new setup.
The pic explains most of it. I plugged the two outer ports on the ends of the intake and used the center port for the vac line that runs to the purge solenoid, by turning the rubber elbows you can get that line to work.
I also had to extend the wires that go to the Intake air temp sensor since the 99+ intake has the sensor on the opposite side of the throttle body.
The bracket that holds the hard fuel line that runs under the intake wont work with the new intake without being modified. I haven't gotten around to modifying mine, the fuel line seems to be fine without it.
I used all my old injectors, fuel rail, brackets, Intake temp sensor,and
You won't see much difference in performance, just a little more low end ummph. I saw no mileage increase.
If you have any questions give me a shout.
On Edit: I just realized that this thread is 1/2 a month old. Did you get your intake installed?