Im running a 1998 F150 with the 4.2L 2WD V6 with an auto transmission. I like the truck a ton and as ive only got about 86,000 miles im considering some aftermarket items to improve proformance hopefully without killing gas milage. So Ill just rattle off my questions and you guys can have at it.

1. From what Ive read one of the most recomended modifications is a gear swap. The recomended is jumping up to a 4.10 gear. Im wondering how difficult such a swap is. Can it be done in the driveway on a nice day? Also does this kill the gas mileage? Im doing alot of city and short highway runs if that helps. Also is it recomended that you pick up a book for your vehicle before beginning something like this or is there an online resource that details the procedure? On reading the VIN you can tell what your stock gearing is right? If so where someone want to post a refresher on reading the VIN # for F150s.

2. Beyond gear swap there seems to be a 3 way tie for #2 of most important upgrades. To go with a new exaust, new intake, or a chip. I would assume exaust over intake because upping your intake is pointless if its got not going out any faster. So if that narrows it down to exaust and chip which looks a little more difficult to judge. From what Ive read chip offers improvement to the transmission and where it shifts at as well as a proformance boost. Does this boost come at the cost of having to run 93 octane? The proformance boost that does come will it be significantly reduced by airflow of the stock intake and exaust?

3. I guess overall a listing of the way a person should progress in which to minimalize bottlenecks in the power increase from part to part.

4. Lastly I get a high pitched metalic chirpy noise simmilar to 4.2L beast in the other post. The diffrence is that I get it when I start up my vehicle with the AC on, I can then shut off the AC and it quiets down quite a bit. Sometimes I dont hear it at all and it is usually more quite once the vehicle is warmed up. Im wondering if this is also likely a bearing in the cam sensor housing or if it could be from the AC compressor or the belt tensioner. Is there a perticualr bearing that usualy fails on vehicles from this year? Also how difficult is something like this to fix?

Oops one last addition. Is there any engine swap that is viable for this vehicle? Ive read that an engine swap is too cost prohibitive but considering the cost of chip, exaust, intake, gears, pullys, headers, and various other additions to bring it up to the lvl of a V8 is it really that cost prohibitive if you can find a wrecked F150 with a good engine in it? Or does the fact that youd still have to swap out exaust and tranny what makes it over the top?

 

First let me say, that I have had first hand experience with all the above except the engine swap.

GEARS: If you want to swap gears, go with 4.10's, but remember, you will also need some kind of LSD or Ford T-Loc (recommended) to compensate for the traction. If you don't, you won't really be able to launch from a start at all. No, installing gears is not easy. If you aren't an experienced mechanic, or at least really know what you are doing with vehicles, don't try it. If you get one little thing wrong, like setting the backlash, torque specs, etc...you could totally blow your gears. Have a pro do it...if you are spending that much money, what's it matter? Also, if you do the gear thing, get some Ford Friction Modifier to go with it. Although this can be speculated, my gears didn't drop my mpg's at all. My mods were 4.10 gears, Ford T-Loc, Diablo Chip, MAC Intake, 40 series dumped flowmaster, and a half-shafted throttle body. I averaged between 14 and 16 in the city...and I was fairly fast for a V6. Without the gears and LSD, I ran a recorded 16.4 in the quarter with a 5 speed tranny. With the gears, I never got to run...traded it in for another truck, but it was quite a bit faster for sure.

GEARS/CHIP:

If you do the gears, you will need a chip or tuner to readjust your speedo. The gears will throw it off by about 10-15 mph. Also, the chip DOES improve your shifts and gives you more power. This is at the sacrifice of gas money by using premium fuel...just the price you gotta pay. HP is expensive, but it's always fun! I would recommend a Diablo Chip or SCT Tuner.

INTAKE:

You are correct to an extent in assuming the intake is pointless without exhaust. The intake will work better with a good exhaust combo. It will work really well with exhaust and a chip/tuner. I recommend the MAC Intake.

EXHAUST:

Tons of options for exhaust...it just depends on what you prefer. Our V6 will never sound like a V8. The sky is the limit...I recommend a Warlock muffler dumped. It has a straight through design, therefore, giving you more power.

ENGINE SWAP:

Never looked into it...and every time someone brings it up...it's way too much trouble, time, effort, and money to handle.

Hope this helps!

 

nope you cant do an engine swap if you live in cali. emission stuff.

My 4.2 ext cab is lifted with 35s. i put 4.10 gears in and its about the same as it was with a 3.55, maybe a little slower. if i were to do it again i'd go with 4.56. i chose 4.10s because i do alot of 100+mile freeway trips. 4.10 gears will definitely quicken a stock v6 but your gas mileage will suck on the freeway. but you will be able to go uphill haha.

as far as the chip and everything, see if you can buy a secondhand chip and get it reflashed. i bought a chip online off someone for $60 and i'm getting it reflashed by motorhaven for $40. i got my exhaust done for like $140, im holding off on getting a new intake till i can find one cheap. oh and the chip means you gotta use 91 octane, not 93.

i hear putting electric fans in to replace the accesory driven one makes a BIG improvement. I'd do that before anything else.

 

Im may look into a used chip to cut some cost off upgrading. With stock tires and no lift, maybe even lowered, I think i should probably see a bit more performance increase.

To do an exaust upgrade isnt it basicly required that you upgrade the stock exhaust manifolds to headers keep the airflow all the way through the exhaust? If thats the case it looks like itll cost around around 600$ for exhaust and headers.

Also im not out in california and dont ever plan on living there. Im down in florida where i dont think there are any strict exhaust or emission regulations.

Exhaust- 300$
headers- 500$
chip- 150$-400$
intake- 150$

At least thats what ive been seeing in my pricing...

 

No, a chip gets reprogrammed for whatever premium gas is for your area. He said 93, so I assumed his premius octane is 93? Don't know for sure. My chip was programmed for 93 octane, but it can be for 91 if that is the highest in your area.

Here's a realistic view of prices:

Exhaust -- anywhere from $100 - $400
Headers -- $300 at the most -- MAC Headers, ever heard of them?
Chip looks about right
Intake is right if you buy a MAC Intake



Also, electric fans do free up a bit of power...more than an intake or exhaust would.

And no, you don't have to have an Intake, Headers, and full exhaust to get power out of it...but the more the better!

 

So im guessing id be looking at something like this for a limited slip diff.
http://www.accuautoparts.com/axledet..._id=AUB:542025

And then throw in this for a gear set.
http://www.accuautoparts.com/axledet...id=MOT:F88-410

Is there anything else I would have to pick up to make the gear swap happen? And I know labor costs depend on where you live and the individual shop but can anyone give me a ballpark number? Im looking at 500$ in parts above and im trying to get an idea of overall cost.

 

I got it all done for $250 at a local rear end shop in my town.

I got a used T-Lock for $150, and I got the gears, used, for $50.

This 4.10's look good, but I've heard bad things about Auburn LSD's...apparently they are fairly weak? I know Tom had them and they stripped or burnt up or something after just a couple of months. I just got some Ford LSD for my truck...they were really strong.

 

Well i think i may soon be a victim of the leaky gasket problem that seems to plague 97-99 4.2L engines so all upgrade plans are on hold and im looking at the possibility of trading it in on something newer maybe a 2000 fronteer or mustang. If I can read up on several people who have had the gasket start to leak, replaced it and then didnt have the engine blow up anyway within the next 6 months then i may just keep it and replace the gasket otherwise its not worth it to keep it as the truck has the same value right now as a new crate engine personally id rather get something newer and reliable and pay than keep something older and pay.

 

Aw man, that stinks. That gasket problem is ruthless.

Believe it or not, I actually kind of like Frontiers...they aren't too bad as far as looks. I don't really know much about the power though.


mmmmmmmmustangs...mmmmmmmm