Yes, the "factory performance" tune is for 87. It's your base factory tune, but you can make all the adjustments that you can to the "diablo performance" tune (gears, O2, EGR, rev limit, speed limit, traction control, etc. etc.). Be advised though, if you start messing with the spark advance or fuel tables you might start pinging, at which point you need to step up to a higher octane fuel - or turn down the timing.
EDIT: oh yeah, and if you just install the factory performance tune "as-is" then it won't net you any power, it does NOT modify the base tune in your car EXCEPT for the changes you made to the options I listed previously