Headers and CAI and it might get up to about 185 RWHP.

The 4.6 wont make a lot of torque,.. too small.

To build HP on a budget you you can bolt on PI heads and PI intake for a guaranteed 50 rwhp increase. You'll spend more on headers than you will for PI heads and intake and get less from the headers.

Or if your on a budget and willing to do your own work. You can port the NPI heads and bolt on a PI intake and you should see about 35 - 40 rwhp there. Add Comp 268HR or 270HR cams and could see as much as 265 - 275hp. With ported PI heads that would put you closer to 280 - 295 hp.

No idea who makes long tubes for these trucks. Shorty headers are a waste of time personally. They have no collector so they have no way to aid scavenging,.. which is what the motor needs to see any hp.

Good luck with your truck.

Hurst