Mike,

I have 3.55 gears now but am wanting to do a swap to maybe a 3.90 something. I know you have a program for the 3.73's and 4.10's but was wondering if you had a program for gears around the 3.90 range. If you do have a program then what specific gears do you have them for? Another another question is: is the R&D on Superchips through with for the 2001 F150's to compensate the speedometer for different tire sizes?

thanks
justin

 

Hi Justin,

Yes, we can compensate for just about any gear ratio up thru 4.10 in these trucks, starting with the 1999 model year, and yes, we can now do the 2001's too!

Just give us a quick call & we can go over that with you & make any arrangments to do whatever custom programming you need.

 

Who sells 9.75" gearsets in 3.90-ish ratio?

 

I really haven't looked into it as far as who makes any, as far as i know nobody may but i do know that dodge has them so i was hoping someone makes something for a ford. I was more curious as of now to see if it would be possible to have a chip to compensate for them.... By the way i see that you have 4.10's. What kinda gas millage do you get? I may end up going with them if gas isn't bad.

 

I've never seen any gears at any company for the 9.75" rear end between 3.73 and 4.10. This rear end has less choice beyond that as well. I'm familiar with the Dodge 3.92s. The chip will fix your speedo just fine. It's a good idea to think ahead as to what tire size that you see in your future as well, so this can be factored in. I'm getting 14city/17highway; the other mods compensated for the gears. Good Luck !!

 

I am looking for gear replacement also and the only thing I have been able to find for our red-headed stepchild 9.75 is 4.10 and 4.56 ratio...

 

Man, i wish some company would make something along these lines. I want more go and don't think the 3.73's would be enough but think that the 4.10's would kill me being as how i do most of my driving in and around town.

 

You don't lose mileage in the city, it's most noticeable on the highway. If you think there's a big difference between 3.73s and 4.10s, buy some 4.10s and increase your tire height to arrive at your desired ratio.

 

The 9.75 rear end used in the Expeditions & Lightnings is a bit limited in ratios, we know of 3.55, 3.73. 4.10 & have heard there is a 4.56 available as well, though we've not tried ordering a set. We have not seen anything in between 3.73 and 4.10 for that rear end, as others have commented also.

I agree with Max on this, go for the 4.10's and, if need be, install a bit taller tire. The difference in gas mileage between 3.73's and 4.10's is really not very much at all, and if you have the Offroad package. you'll actually get *better* mileage with 4.10's due to the very tall tire that comes with the ORP making the motor lug below it's power band much of the time. In our '01 5.4 Lariat w/ORP, it has the 3.55's and so 90 mph is just 2400 rpm in Overdive, now *that* is beyond tall, and needs 4.10's from the factory in our opinion.