HI!... I gained 19RWH.P with the install of KOOKS SS LT headers. This was on a full bolt on 5.4 N/A. (251RWH.P/330RWTQ at 200,000kms)That was with stock heads and cams. I installed the same headers on my built 5.4. Don't know what increase they gave me on it. But it was 8.0:1 compression with turbo grind cams (engine was built for turbo set-up) and in N/A mode made 354RWH.P and 392RWH.P. So yes headers work even in N/A trim.

 

Right - and they help improve MPG too...

Did you happen to notice the part about "boost" level in the HP statement for the sales brochure ?? What do you suppose that level is in N/A trim ?

More air in means more air out - simple enough.

A boosted engine flows more air - period. Hence the part about a boosted engine seeing a better increase from headers than a N/A one...

Never mind the physics - keep arguing...

 

Hey buddy i also have a 99 with the Triton i have it supercharged and performance plugs and am knocking on 430 with just supercharger alone! Def worth the money and mine has 38's on it can only imagine what it would do with something that low to the ground!!!

 

Way to go - this thread died over 5 years ago.........

 

Just because the thread disappeared 5 years ago doesn't mean the thread can't be added to. If you go to the general discussion area, you'll find a thread that has been going for well over 5 years. Give the guy a break!

 

Ruff, do you have any pictures of the truck?

 

Glad this one was bumped to the front. It's a pretty good read. It kept me interested enough to read every post lol. I recall when this thread happened, I just installed LT's on an 98 non-PI/NA 5.4L. The 98 is still running the factory tune lol. Never touched the tune in that truck and still have it. Man, I wish I would have Dyno'ed before and after the LT's. I don't know how much I gained, but recall it was a noticeable improvement. I picked up 6 seconds from 0-80. The 3" X 2.5" HF's were welded directly to the collectors. Mandrel crossover/Nothing over 2.5" from the cats back. SISO/Magnaflow muffler/Factory TP. LT's alone helped my old girl. I was around 200,000 miles before they went on.

I wish all of these guys were still around. Good thread to read.

 

I did the same haha! And I can't wait to invest in LT's... I'm about to start on reworking my cage for my fuel cell to get ready for the custom dual side exit exhaust out the fiberglass!

 

Yeah man I do im at work but when i get home ill post some pics to the thread of the truck and charger under the hood.

And thanks to all those who commented i didnt know there was an age limit on post hahah

 

I think out of all the upgrades ive installed so far the underdrive pulleys and throttle body added the most noticeable difference the truck revs and performs alot more aggressive. I have the FlexALite fan kit sitting right behind me but I'm debating sticking with the stock fan clutch setup

 

Swapping to LT headers and true dual exhaust is still the best mod I've done to my 99 5.4 F150. I haven't tuned mine so you do lose a little off the line torque, but mid and top end power is VERY noticeable. Future plan is to replace the stock fan with 2010 electric fans and radiator

 

I know this is old but I saw the bit about CAI. Thing is they don't increase HP or performance. There is so much data on this. It's nothing more than snake oil in reality.

 

I got a good bump in power from my Superchips programmer. I think it is a good program for stock engines. If you modify the intake or exhaust you may need a custom tune.

 

This is yrs late, but I would save more on top of that 3k. 2k more for $5k promar would square you a way with a built long block support of 18 lbs of boost . Not bad if you ask me , I have a 2004 f150 5.4 3v , they ( promar ) has one for me to. And stock my truck is 300hp and 365ft torque and then add my boost of 18 I'm pushing 650hp. 15 psi of boost will double the the base horse power... They have them up to 24 psi of boost but are like 10k with all 1 yr warranty. They kind of call them their revised lightning.

 

What the rough cost of all this?