I am assuming that you guys have a 9.75" rear ends in your trucks, I am looking into swapping over to 4.10's with my 22's on my truck, but I can find what vehicles came with 4.10's???? or did you all buy NEW aftermarket gear sets?

 

Yes.
I don't think 4.10s are offered on a production Ford equipped with the 9.75 rear, but I could be mistaken.

 

I dont think so either. Mine are ford racing gears

 

I was quoted $750 total after parts and labor. Does that seem right or can I get a better deal?

 

My 2005 Screw with a 9.75 rear-end had 3.55 LS stock, and I went to a Ford Racing 4.1 setup for about $600 installed on my 2wd.

The difference is definitely noticeable, but to be honest if I could do it again I probably would have gone 4.56. I didn't at the time because I thought I might supercharge someday, and at that point traction off the line would have been a real problem.

Also, my tires are only 32 inches tall, about 1 inch different from stock height. I think it was like 5-6% change. The 4.1 is very drivable for me.

 

I changed from stock 3.55 to 4.10's ,finately manual shift with 265/70/17's and it definately was a huge improvement in acceleration and torque! Didn't notice much drop in mpg,It sucked from the getgo anyhow !? lol!

 

i switched mine out from 3.55's to 4.10's. i have the 9.75 rear end and 20" wheels and running a 275/45r20 toyo proxes s/t. noticed a HUGE gain off the line, but the top end died. without the supercharger and just my edge tuner, i couldn't get it over 105 on a dead run.

I DID however notice and increase in mpg (I do alot of city driving) with the stock tune right now i hit about 18 mpg (16mpg before) and with an extreme tune with my edge i'm at 15.1 mpg.

should be throwing my supercharger and everything back on this weekend.

oh yeah. if you're asking how long it should take you to change your gears......


DO NOT TRY TO DO IT. my truck was apart on my lift for almost 2 weeks while i was tinkering with it trying to get it right.

don't try and cut corners on this. it won't work. spend the money and get it right

 

Yeah I agree, if you havent done it, let a pro do it, and watch him do it. Crash, I cant believe you cant get over 105. At 100 in 3rd gear im at 4500rpm, and I still have 1 more gear... Do you not have the power or are you in OD at redline?

 

not redlining so i'm thinking more on the power side. I'm customizing me a good program for the edge now though and we'll see how she does. getting a custom tune made to throw in my predator for the supercharger so that should help big time when i reinstall it.

 

Something isn't right...your top speed should be higher with the 4.10s.

 

ummm you sure on that killer? i THINK you have that backwards.....

or am i wrong?? because with the 3.55's i had ****ty low end with good top end but now i have killer low end with crappy top end

 

You mean just the opposite, lower gears(higher the number) will slow you down up top.

 

That's not what I mean at all.

No matter how short the gears you install, you won't reach redline in top gear. While your THEORETICAL top speed with 3.55s is higher, the gear is so tall that you can't pull it.

4.10s will allow your to pull higher revs, much closer to your power peak.

Consider many sports cars with 6-speed manual transmissions.
Theoretical top speed is much higher in 6th.
But in reality, top speed is reached in 5th.
Why is this? because 6th is too tall to pull.

My Expy pulled well over 130mph in 4th gear on 4.10s, and I had plenty of revs left (but ran out of courage). I guarantee you it wouldn't have done that with the 3.31s that I had in there originally.

Neal the HP freak has 4.10s with small-ish tires, like 29 inches.
He's posted a top speed of over 150mph.

Trust me, the 4.10s are not going to limit your top speed to 105mph.

The following misconception is patently false:
Lower gear = better low-speed acceleration, while taller gears = better high speed acceleration.

The truth is:
***Until you reach redline, lower gears provide superior acceleration AT ALL SPEEDS***

 

bud, i don't know how to say it, but i think you just changed the way ALOT of people (not just ME) thought of something. I've read you're other posts, and you don't seem to be too far off on most stuff, so i'll go with ya on this. I've HONESTLY never thought of it that way. everything i've always read or heard

smaller gears=better top end
higher gears= better low end




oh yeah. kudos man. (and this is not a sarcastic remark either)

 

Think of it this way:
When you are on the highway and you want to pass someone, do you:
A. Upshift to a taller gear because it provides better high-speed acceleration?
or B. Downshift to a shorter gear to get into the meat of the power curve?

Short rear ends killed top speed back in the day, when cars had narrow-ratio 3-speed or 2-speed Powerglides. But these trucks have wide-ratio trannies, geared very tall for MPG reasons.

On my Expy with 4.10s and street tires, I towed in third. Yet I was still under 3000 rpm at 65 mph. OD was too tall to pull comfortably at towing speeds, even with the supercharger.