i installed a set of the JBA Stainless Steel headers on my 07 4.0 a few days ago, the quality of the headers is awsome! no slag any where or pin holes in the welds(as far as i could see)
all the hardware was not included. but i chose to reuse the factory studs and nuts except for a few bolts where there werent any factory studs.
removal of the factory manifolds was real easy! just took a bit of manuevering(sp) to get them around any hoses or wires.
the install of the JBA headers was a bit more challenging due to the larger size and tight spaces in the engine compartment.
i found it easier to unbolt the y-pipe from the muffler and loosen the mid section of the y-pipe to allow more movement.
once the JBA headers where fitted up right the nuts went on smoothly. and the new bolts went in the extra holes without a problem. excpet where my dad stripped out a hole in the head.
once everything was connected and torqued down(13ft lbs) i had to bend the EGR tube out a little bit, as it was rubbing against the header and im sure it wouldnt have made a difference if it touched or not, i just did not want to hear a tapping sound when it vibrates or moves around over bumps in the road.
after i checked all the bolts, and clearances, i started the truck up and through the stock exhaust i could not tell any difference in sound, so i pushed back the muffler to run straight pipes after the cats and it had a low rumble to it.. with the 3k rev limiter while in park, it didnt get raspy at all.
and since it was raining all week in houston, today on my drive back to san marcos i was able to see what kind of gains i could feel.
-Gains After install of headers-

Low Range- no significant gains in power, just felt let it was breathing easier.(i dont know how to explain how it "felt to breathe easier" so ya.. ha)

Mid Range- Deffinate increase, 2500-3500rpms is where i felt the most power increase. when cruising at around 40mph and floored it, it will hesitate for a second and then throw ya back in the seat(by hesitate, i mean it is gaining speed steadily and then BAM gains speed more quickly)

High Range- it seemed to feel smoother while driving and passing. with it all stock when i passed someone on the Hwy, i could hear the motor working harder to gain speed, with the headers, it wasnt straining at all and was quick and smooth as i passed them.

i will have pictures of my install and comparison on the headers next to the factory manifolds when my dad gets back from amsterdam, and ill have video of the sound thru stock exhaust and no muffler, and ill get a video up of the truck at the 1/4mile track with muffler on and off to see if one yeilds a faster time.


overall, i am very pleased with the results! i am sure some claim no noticeable gains, but that is not the case for me. i am very happy with the improvements i feel i have gained.

after i install pullies, e-fans, intake,exhaust and a programmer, i will have the truck dynoed on stock tires, and again after i install my suspension, 4.56s and 35s...

 

Thanks for the feedback.

Rich

 

nice

 

sweet cant wait to see the results

 

for sure! im waiting on going to the track myself!
ill go to the track sometime after jan. 9th when my brother gets back to san marcos cuz he always goes with me.
i do hope my 'review' of the headers helps yal decide yay or nay if yal are thinking about getting some. i will post up mileage increase/decrease next week as i know this tank will be crappy since i was testing out where most performance was..so needless to say my foot was in it alot! haha