Hi guys, I have a 02 f150 4x4 xlt with the 4.6l v8. Now I no there's a lot of mod posts for these motors, but I have some questions that werent answered by them. First off is I just ordered new tires that are 285 75 r16s. The tires I have now are 265s. And my stock tires according to my sticker are 235s. So I no I will have to recalibrate my speedo. But before I do that I was wondering if I should put different gears in my truck. What size gears? I no that if I go to big like 4.56s il lose a lot of mpg and I don't want do that. So would 4.10s work or no? I just want that power back that im gonna lose..and maybe a bit more. But should I wait to recalibrate for the new tires after I get new gears to? Also, I'm looking for some more tq. Especially in the dead range of 40-50. I was looking into long tube headers? Summit racing has a pair for 270 bucks that are by paceSetter. Also I figured since they're already separate I might as well run 2.5" true duals with maybe 3or 4 inch tips. Will that make me lose or gain power? And lastly I've been dobbling in my head of the idea of a chip.. My buddy put one on his diesel and it made a difference. Would a chip increase power and mpgs a bit? And last but not least..after all is said and done,should a tune be done to my truck so that all the mods will work optimumly and give me the best they can? Thanks guys

 

Alright I can help u on all of ur questions. I'm running 35s on my truck and my Speedo is only off by like 2 to 5 mph. And yes getting lower gears will give u back that lost torque but that'll cost u 1k if u put them gearing in it self. Personally I wouldn't waist money on that. Maybe if u were running 38s then yes. And yep long headers will give u more power along with the true dual exhaust. That'll give u about 20 to 30 more hp from stock. And yep a chip will give u more power but less mpg because it mainly just tells the injectors to pump out more gas along with advanced timing. Now u can get a programmed one where u can hit power for more power or eco for better mpg. Only other suggestion I have would be a higher flowing intake. Other then that it's either dropping in a 5.4 or super charge it

 

First your truck weighs nearly 6000 lbs with gas and one passenger.
The 4.6 is a small displacement such that it has low torque below about 2500 rpm.
Long tubes headers may help a little but don't expect a big boost for the investment.
Stay small with the pipe size because higher internal gas speed is important not the big volume slower speed of larger pipe size..
Then there is the hassle of connecting to cats and placing OX Sensors.

Gong to larger tires, if you don't go off road were their needed more, is more for looks and creates the extra expense of changing front and rear gears..
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The motor only begins to make good torque above about 2500 rpm and peaks in the 3200 rpm range and HP peaks at 4000 + rpm.
In OD your presently at about 2000 rpm at 65 mph so throttle response is very low without downshifting.
.
Consider your trying to gain performance below 2500 for normal driving that is very hard to do.
The lower gearing multiplies engine torque at all rpm.
Exhaust gains very little and larger tires makes it worse.
.
There is no comparison between the gains a diesel gets from a chip or program change and the much smaller gains for a gas motor.
The two engines are so far apart in design and size.
The total expense is high for the returns you get from all the changes.
.
I just gave you some things to think about. It's your money and time to decide what you want.
Good luck.

 

That is very good info. Thank you guys! So since I got the 4.6 I understand that it's just not a powerful tq monster, and that's ok. I new that when I bought it. I just wanted a little more pep out of her but it seems it takes a lot of money and or time just for some minimal gains. So I think all I'm going to do is hack off some cats and maybe just put in a free flowing muffler and keep the stock exhaust. And I already did the gotta mod for intake. The only other thing I'd do is put 4.10s in. But because of the price, I'm just going to drive it and save up until I get enough to have it done. And il be satisfied. So again. Thank you guys!