gibson part number 3515 to be exact I tow fragrantly its a 4.6 so no one that i know makes long tube are they worth it. . . I'm considering this beacuase my engine is out and that way I dont have to pay installation cost

 

people say it makes no difference in power. definitely is easier to work out out of the truck so if you gonna do it, may as well do it now.

be sure the gaskets are good ones so you don't have problems in the future.

 

Well if it those not make a difference I'm sure I can find other things to do with $450

 

I say do it I have heard shorties help with bottom end

 

Don't wast your money on them!
Gibson makes a nice header but they don't help whatsoever.
Had them on my 5.4



Phil

 

Do you fart a lot when you tow?

 

I've never pulled a 4.6 but imagine they are similar to the 5.4. I wouldnt be so sure theres room to install the shorties while the engine is out? Not a lot of room on the fender side firewalls when they come out or go in. I duno.

 

I heard shorties actually hurt low end torque.

 

Sure you can install them wile the motor is out, But the question is,,,,,will you be able to get the motor back in with them on it???

Phil

 

FWIW, I was involved in dyno testing shorties vs stock and long tubes vs shorties on a late model GM 5.3L. The shorty system picked up 8 peak hp over stock and while peak torque didn’t change, the dyno graph showed some changes in its location in the rpm range. The long tubes picked up 21 hp over stock and 13 over the shorties. Peak torque jumped 10 lbs-ft over both stock and the shorties but it was above both stock and the shorties all the way across the graph, especially at the upper end. They were able to squeeze a bit more out of the long tubes with some custom tuning.

Couldn't say for sure if the same applies to Ford modulars, but I'm not sure I would spend $450 for 8 hp.

I forgot to say that the 8hp included a cat back system.

 

have the magnaflow full exhaust and my bad their BBk

 

Joey (built54) did the Dyno comparisons for the 5four. From factory to shorty's, same, no change. From Shorty's to Long Tubes, - graphed a 30 hp gain with another 35 torque. That's the only Dyno I know of for the truck engine set ups.

 

I did the pacesetter longtubes and wouldnt look back. Totally different truck. i would call it at least 20 hp on a 5.4. If you live in California ( like me) You will need to find a shady smog guy. unless you would be willing to change it back every 2 years.

 

Interesting. That follows pretty well with the GM 5.3 tests I referenced above. I think this is a case where "common knowledge" is correct. Do long tubes or save your money, I guess.

 

plus the power under the curve is where it matters, not just the peak's, unless you are holding your dyno sheet whilst towing or racing