I have found a source for long-tube headers to fit my '99 with 4.6L. Years ago, I read an article in Car Craft or Hot Rod or something that talked about rpm and tube length. The point was the lower the rpm the engine operated at during cruise speed, the longer the primary tube should be.

Anyone have ideas? My rpm is 1750 - 2500 on the hwy. Will I notice any difference in torque or gas mileage with long-tube vs shortie?

Thanks.
Curt

 

where did u find a source for long tubes on the 4.6l the mustang LT's wont route propperly they will hit the firewal... i been looking for LT's for mine... what kinda price are they?

 

Todd says, "The 70-1326 is a shorty header, the 70-2226 is the long tube for your truck. You won’t find that part number on the website as it is brand new. Both sets are coated in & out with our Sterling finish, so you get our lifetime warranty with them as well.

Call 800-432-3379 x112" They can give you the pricing.

Here's the website:
http://www.jet-hot.com/pages/Precoats/FordTruck.htm


Opinions on the long-tube vs shortie headers performance?

 

shorties u see almost no gain over stock manifolds long tubes u will see about 20ftlbs gain and likely 18hp

 

definately go with long tube headers! A friend of mine owns a performance shop and has a dyno in shop and we ran a test on the same engine block with all different sizes of headers and consistently throughout the whole rpm range long tube headers with large collectors give you more power. while shortys give you smaller gains throughout.

 

Thanks for the info; I found a dyno shop in Pflugerville that allows 3 runs for the price.

Faster -
What is your info source for the hp/tq increase with LT headers?

Thanks.

 

going off of what dynatech says the LT's for the 5.4 add then just subtracting the avg percentage difference in headers for the 4.6 and 5.4.... so those numbers would be about right if not then just check the gains for mustang..

 

If you do decide to go for long tube headers, heres another choice.
Dynatech
I'm really thinking about getting them, but I'm afraid it will too loud. Dont want the niehbors attempting my assasination after a few 5:00am startups.
I already have a borla catback. I was going to replace just the cats next, which had to be welded and expensive to intall, I figured with this being a completely bolt on kit it would be a better choice.

 

speaking of dynatech supermaxx headers, anyone install these? dyno numbers?

 

hey i got some bad *** BBK 1-5/8 in. Headers for 97-03 Ford F-Series/Expedition w/4.6L (Ceramic) for sale
Part#: BBK-35150