you guys put too muc emphasis on peak gains. The main benefit of long tube headers mainly is that they flatten out the torque curve and make a lot more torque at higher rpm where the 5.4 usually falls on its face. This is what I was told by Mike Troyer. Im assuming in some cases the shorties may not for everyone do the same thing just not to the same degree as the long tubes

 

Who's you guys? Without anyone from any shop or any forum board telling me how much power they did....or subsequently DIDN'T make I can tell from that dyno graph that ****acola made almost 40lbs ft of torque at the wheels with his system. Some might be here with "Built" trucks for top end, but towing and off-roading are 2 of the main roles my F150 assumes in day-2-day life and 40lbs ft of torque in the heart of the midrange is very much an eye opener for any NA mod...period

 

When you installed the shorties what did you have for a cat pipe?

 

the same high flow cats as with the long tubes.

 

So the longtubes made an additional 30/35 over a dyno that already had high flow cats in place?

 

yes sir.

 

Very nice, can't wait to get mine dynoed......