What kind of gearing do you have?

 

 

There are quite a few threads regarding the costs...here is one from a few years back... 4x4 Gear Change Cost Moving from 3.73s to 4.30s might be a good long term strategy.

 

With 35" tires at least 4.56, 4.88 would be optimal. Exhaust Y pipe, 5 star tune and you will have a peppy trucks, if thats not enough force induction is the only way to increase HP and TQ in a 5.4.

 

Re gear the truck, 4.88s if your planning on 37s. After that you can take a look at a tuner or other options. Best bang for your buck is gears. Tuner is not as effective on the 2v/4r100 trucks as it is on the later 3v or diesels

 

 

Ok take this as you want, I've been down this road already with my 5.4. Throw that intake and throttle body spacer in the trash, spend the money and get custom long tube headers made with a free flowing ypipe if you want real power. You'll need 4.88 years for 35" tires MINIMUM and with 37's go to 5.13 gears. A tuber wont help anything on these 2valve motors except altering the shift points higher other than that no power gains at all. Your best bet also is to add the newer high flowing PI heads and intake

 

And if you really want power install the 4.6 power adder for mustang's but order parts designed for low end power not high rpm. Then buy 4.6 intake spacers and bolt on a 4.6 intake from a mustang and your gonna have to get dyno tuned

 

Alright so trucks coming out of paint shop this week then 5.13 gears like you recommend. Since I’m doing the gear change I was thinking of putting a ox locker in the rear what’s your opinion on that super duty scaller?