Well since you have a 99, you have split port intakes which fromt he factory flow extremely well. It's hard to give hard numbers, but you can pick up about 10 hp from porting the intakes. When you port them, what you do is remove material from the inside to allow for more air to flow through them. Basically think of bottles one is 20 oz and the other 1 liter. What one holds more air? The 1 liter one. Don't follow this motto to the "T" but the basic rule of hp is more air = more hp.
60' ~ 2.1, 1/8 ~ 9.61 @ 73.4mph
Living one day at a time!
DAMN Those are some old *** numbers!!! I need updated ones!!