i have a 99 f150 5.4L motor and getting it rebuilt and i am going to get some exhaust headers to replace the stock manifold
and what is the differance between the shorties and the long tube headers
what porformance gains
any fit problems
and mainly after fit sound?

 

shortys will bolt right up to your stock y pipe. long tubes pretty much mean new exhaust all the way back

 

If you use any header other than stock be prepaired for some loss in low end pulling power.

 

I dont think that is true, Shorties can build lower end torque, by equalizing scavenge between the cylinders. The flow is as much of a gain as having the same length of pipe for each pulse to travel along. Im not going to go into exact description unless someone wants me to.

 

Header will even out the distance that the exhaust travels to meet at the collector for all cylinders. With all tubes being the same length, exhaust performance goes up as does power. Shorties will help more with high end (loss in mid and low range) and long tubes will help boost low and mid range power. I had a set of shorties (JBA) on my '97 5.4L F-150 and was pleased with their performance and quality (lasted 10 years and sold it with them still on). When I bought the truck in '97 the only thing I could get was shorties (not much room in the engine compartment), but maybe somebody has come along in the last decade to make some longer tubes.

 

Long tubes all the way....had both and the LT's pack a larger punch all the way through the rpm range. There only 2 kits available that have the complete bolt on with a y-pipe...Dynatech, and OBX which are Dynatech knockoffs. Both are made of high grade SS and fitment is great. If you want the best then look at a set of Kooks, but the are mucho $$$.

 

Im pretty sure you have that backwards. Shorties produce bottom end while long tubes produce high end.

 

I wouldn't bother putting shorties on if you are doing it, as said above Long tubes give the best performance but are harder to find and more expensive.

 

I corrected stand about dislexya my...

 

so this leaves you in a bit of a quandry! give up bottom end for some top end or get more bottom and have less top? my mods so far (fan, tuner) seemed to add low end mostly, but would that be negated by adding LT? This was actually my next planned mod and I thought I would go LT, but now I wonder.....

 

vote goes to long tubes!

 

With shorties you wont loose top end, you just wont gain any over stock manifolds. ( Corrrection, depends on how bad the stock manifolds are, they could still produce more power everywehre) Long tubes offer the largest gains, most of which is Mid-Top end. With loss's in the bottom RPMs normal due to the loss of back pressure.

 

Long tubes will give more hp/trq over the entire rpm range.....trust me, I know. I would like to add that they really excel in the mid-upper rpms, but will help with low end as well to a lesser degree.

 

My vote is neither, triple-y headers are even better than longtubes, more torque and power across the entire range.

 

Long tubes for the win!
The Kooks are cheaper then the Dynatechs.
OBX are even less $$$.