The actual Dyno sheet you see on JBA's site is for MY truck. It was done without a speed limiter and with SIDO JBA exhaust (K&N sold theirs to JBA a few years ago). My truck only has a 4.6 and 3.55 gears on stock rims. I got the SC edition so there is extra body weight, but after the headers and SIDO exhaust, I was able to burn out pretty well. I consider the gains pretty impressive from the standpoint that I have a smaller engine then the fx4 and the gears are higher too. When I gear down, I'll be sitting pretty fat. JBA's are expensive, but you really get what you pay for. The metal is uber thick and I upgraded to the ceramic coating for like an extra $40. or what-not. I used to have some sound clips available. I'm sure a search could dig them up.

 

so having first hand experince do you think its worth doing on the new 5.4L 3V engine....i currently have a magnaflow SI/DO exhaust....

 

About a month into having the headers I got a code for exhaust gas emmissions. We trie all kinds of things to narrow down the source. And for about a week, I was header-less.........that was the saddest week of driving I had in a long time. Now the code was totally unrelated to the header in the end, and I sure as heck was glad to get my headers back. The very same day I got them put back on and took it for a drive, I told my wife--I'll never have another truck without headers. They're just that much fun! I only wish I bought my truck during the family pricing and was able to afford the 5.4 ....:-(

 

I got put a set of Pacesetter longtubes on mine on the dyno saw 20 RWHP and 25RWTQ and I'm still emissions legal. so are those numbers worth it? to me yes it was.