Don't know which I should go for. Either one will keep me under 3 grand on the interstate, and I'm not overly concerned about speeds over 100. Has anyone used the 4.30 gears with stock 265/70R17 tires? I would like something pretty aggressive, and I would think prices are fairly close.

On the other hand, I've heard countless stories of people with 4.10 gears that have never looked back. How aggressive are they?

Eventually, I will get a supercharger. Before I do that, though, I need to get all the necessary fuel modifications over the next year. Right now, I want gears.

Any input is appreciated.

-Flea

 

Hey Flea, WLF has 4.30s on his truck. Still better yet, he just completed a long trip so he might also be able to give real world figures on gas mileage & RPMs at highway speed.

I went to this calculator to figure what RPMs would be like at highway speeds and thought that 4.30s would be tolerable but it might be different in real driving conditions?

If I ever get the money together I would like the 4.30s myself. I imagine it would make my 4.6 a completely diferent animal.

Good luck.

 

I'm not really concerned about mileage... gas isn't too expensive for me, even with preimum. All I want to know is how it accelerates compared to 3.55's and towing differences.

-Flea

 

I have the 4:30 gears and love them. I did just go on a long trip but was pulling a 5th wheel trailer so can't speak to mileage. I was able to pull a 5000 lb trailer at speeds exceeding 80mph using my 4.6L engine.

Initially my mileage seemed to get better even with the speedometer corrected. Plan on correcting the speedometer very quickly since the timing of the engine will be off until you do. You will need the 23 tooth speedometer gear. It will get you close.

If there is any draw back, my gears have a faint wine at about 40-50mph. Can't hear it with the radio on but it is there. The taller gears do have some noise to them.
The 4:30's are the tallest that will bolt strait into the housing with no other mods. Do the bearings and seals while you have the case open.

These gears really change the performance of the truck. By far the best bang for the buck so far.
You will see my tire size in my signature, I think our tires are close to the same diameter.

 

They are fairly close in size... as far as the whine, I've gotten used to a whistle from the FIPK and TB spacer, so I'm sure I can get used to one more noise. Besides, I usually have my radio on, so like you said, that shouldn't be a problem anyways. Thanks for the reply, and sweet truck.

-Flea

 

I am debating about changing gears due to the fact that my tires are 315/75/16's and my gear is only a 3.31. not sure what gears i want. after what i saw about the being able to haul quite a bit of weight with the 4.30's and only a 4.6L i was thinking heavily on them. but then i saw the thing about the transmission speedometer gear and timing problems. I thought that the speedometers on the newer trucks could be programmed? Also with the big tires on my truck in effect my overall ratio would be closer to that of my truck when it was stock i think. (well actually a little lower than that but closer than if i had stock tires and 4.30's) Would I have to change the speedo gear due to the large tires that I have? Like i said I thought you only had to have the speedo programmed.

 

I wouldn't plan on running 4.30s if you've got a 4x4. I have yet to find anyone that carries 4.30 gears for the 8.8 IFS. They make them for the 8.8 and 9.75 which if you have a 2wd is fine cause all you have to gear is the rear axle. 4x4s have the choice of 4.10s and 4.56s. If you've got 33s then 4.10s will work fine, 4.56 is gonna be pretty deep for that size tire. If you have 35s, ESPECIALLY if you have a 4.6L, get the 4.56s. 4.30s aren't even deep enough. I'm suprised you can even turn the tires with a 4.6L and 3.31 gears. I've got a 4.6L and 3.55 gears and its bad enough. With 4.56s and 35s its about the equivalent to having 3.73 gears so its right at stock, and if you do any towing or hauling this is the gearset you want. As far as setting the speedo, 97/98 trucks have a VSS gear on the side of the tranny or transfer case (2wd/4wd respectively). 99+ F150s are computer controlled so they need to be reprogrammed by either a dealer or get yourself a microtuner.

 

Couple questions. What is IFS? Also, what about the comment "The 4:30's are the tallest that will bolt strait into the housing with no other mods. " made by another poster on the forum. Is that true? If so then I am gonna have to go with the 4.10's. according to a chart i have here at home 3.90's would give me back my stock ratio. 4.10's would give me the equivelent of a 3.55 and 4.56's would give me a ratio of roughly of that of a 3.73. just thought i would pass on that info. In case you are wondering I got the info from a reider racing catolog.

 

IFS is independant front suspension.

Since my last reply in this thread I have had the the 4.30 Precision Gears installed and have about 3,500 miles on them. Mine do whine a little at certain speeds/throttle positions, it is slight and does'nt bother me though. I still have my stock tires and my RPMs on the highway are 2,000 @ 60 MPH ... 2,500 @ 70 MPH ...and 3,000 @ 80 MPH. I dont monitor my gas mileage so I cant tell you any change in mileage. But talk about a change in performance!

I would'nt reccomend such a dramatic change for others, truth is I mostly drive around town and average about 4K miles a year w/ my truck. It has long been established that the best all around ratio with these trucks is the 4.10s.

I checked out the Reider Racing calculator for effective gear ratio and it did'nt seem right to me. They show that a taller tire diameter will yield a higher numeric ratio? I know that taller tires lower RPMs by lowering effective ratio .......... dont they? I hoped to go to 33" tires eventually and wanted to figure out my effective ratio. Anyone else have a formula for this?

Thanks in advance.

 

You can "test" the effects of 4.10's by getting some smaller tires. To figure the right size, check out the RPM calculator on at Randy's Ring and Pinion. Click Here. Select RPM from the list on the left.

Put in your stock configuration: For me it is
Ratio: 3.55
Tire: 30.05 (from the Tire Height calc. - 255/70/16)
MPH: 65
--> RPM=1803 in OD

Then change Ratio to 4.10 and see the new RPM (2082 for me).

Now set ratio back to 3.55 and vary tire size until you find the same RPM as the 4.10.

For me 26" tires will duplicate the effects of a 4:10 rear end. The tire height calculator will help you identify the tire size - for me, 255/50/16.

Finally, find one of those used tire places to pick up a set of smaller tires for dirt cheap prices.

TADA! Hopefully for a fraction of the cost of a new gears, you can try 'em out. See if 4.10's are too much or not enough....

 

How much does a 4.10 swap cost? How mechanically complicated is it to do the swap (any pics or links appreciated)?

 

4x2 - look for about $5-800 with install and all proper components
4X4 - look for about $10-1800 depending on the same

-Flea

 

I got a quote for my truck which happens to be a 4x4 and was considering 4.10's and he was gonna charge almost $2000. I think I am gonna wait and put 4.56's in my truck. I can buy the parts myself and have someone put them in for me. I know a guy that is the head transmission guy at a nearby ford dealership and he does stuff on the side at home for quite a bit less. I am hoping to get my install closer to about $1000. I can get the gears cheaper myself and the other parts i need and I know the labor is gonna be less than the $80 an hour the shop I got a quote from. The owner is the former head mechanic for Bigfoot and is pretty high in his prices.



Also LE PEW, Reider Racing calculator is for what gearing you need to change to when you go to a different size tire not what ratio your tires will actually be running at with the stock gears and larger tires.

 

What do I look for when I'm searching for the gear set? Ring and pinion? 4.10 gear set? I'm not sure what parts are actually swapped out in the diff

thanks for prices...

 

you will need a set of 4.10 gears. summit racing has them and you will need an install kit. silicone wouldn't hurt either. differntial oil will be needed. depending on how many miles are on the truck you may wanna go ahead and change the wheel bearrings. they are fairly inexpensive and since they have to be removed anyway it is just a good thing to do so you will not have to do it a few thousand miles down the road. that and it isn't gonna effect the time it takes to change the gears anyway.