How much of a HP increase can i expect??

Ok guys I am doing a full PI swap this weekend. I am considering placing and order for the following parts...

Steeda underdrives
tuneable inductions stage 4 intake kit with Pro-m meter
Dragon upper plenum and 75 mm throttle body

Ok guys I already have a bassani catback with a Mac O/r H pipe and a set of 4.30's in the rear.

What kinda numbers will I see with the PI head swap and those parts I just listed?? I think i will be around 285hp to the flywheel does that sound right?
 
With some really good driving u might be able to. It just depends on the trans. and the driver. I've raced a '97 Z28 w/a CAI and flowmasters, it's an auto, and I beat it everytime we race whether it's from a roll or a stop. It gets me on take-off everytime tho, because I SUCK ASS at launching. Go find one, race it and let us know how it you did :nice:

EDIT: I've got ~258-260 rwhp in my car & it's a 5-spd.