I'll let dyno runs tell the story and everyone I've seen for 5.0L's with just a CAI and tune net around 30rwhp...which is 100% impressive but far from the 50-60rwhp you refer to...unless you not referring to rwhp.

The 5.4L IMO won't see the 10-15rwhp with just a tune and CAI... There isn't that much power in hiding. As it is, the truck can't use all the air the stock tubing is feeding it. It's easier to look at parasitic losses as a percentage then a rough number.

Manuals: 12-15%
Auto: 30-33%

So the rwhp numbers from your Harley is pretty spot on to what it was supposed to be. Depending on what kind of blower you had... could have had some fun low end torque!

Your bullitt is a nice looking car and always been partial to that shade of green... any dyno sheets on that? Sickens me that my blown 01 makes 381rwhp with LT's, x-pipe, catback, C&L plenum, and 8lbs from a vortech and '11's are making about that stock. Only saving grace I got is my car weighs in a 3300lbs (aftermarket k-member and a-arms, coilovers, bbk wheels). Cause I don't get much a chance anymore to show it off (and just spent the weekend detailing it:







Little bit back on topic though... Not terribly sure how the Navi is a POS. Although I'm not sure I would have paid the full retail price for mine, it is on par with the likes of it's competitors in terms of fit/finish/quality. Least for my year straight from JD:

Reliability
Review Last Updated: 3/12/09
The 2008 Lincoln Navigator reliability score of 10.0 out of 10 is the Predicted Reliability rating provided by J.D. Power and Associates. This score is based on trending the past three years of historical initial quality and dependability data from J.D. Power's automotive studies, specifically the Vehicle Dependability Study (VDS) and the Initial Quality Study (IQS).

Not bad for a POS domestic IMO