tallwelder

I will say in My experience Ford has the best gearsets on the market. I don't know the answer to Your question.

rts9364

My guy told me that with FRPP gears and brand new diffs (1500 miles), he wasn't too worried about doing anything more for break in than taking it easy for 500 miles.

Toprat

FYI, Ford does not make the FRPP 4.09, it's made by US Gear

Larryw1

i had trouble finding gears for the rear of my truck. My rear diff is a 8.8 not a 9.75
I bought 3:73 gears from ford frt and rear. The kits were priced reasonably. Less than $500 for both gear sets from ford.
My truck is slightly lower geared than stock. With the 35" tires. When my speedo reads 70 my gps shows 74 miles an hr. No gear noise very quiet.

JB 1 TIME

I have the super 8.8 in the rear too. You have to order the 4.09 FRPP gear set for the rear. The "regular" Ford dealers I talked to didn't even know there was a 4.09 that would fit the super 8.8. They pretty much laughed in my face when I told them that. Idiots. I had to find a dealer that distributed Ford performance parts. Ironically that was the smallest dealership in the area. A very small dealer.

khsonic03

How much did you end up paying? I got a quote from my dealer and it was $2500 for front and rear. Crazy.

JB 1 TIME

I paid $2200. I used a local driveline/axle shop near me. $2500 for both axles at the dealer is much cheaper than some quotes from dealers I've seen. General rule of thumb is that each axle should be roughly $1000. Mine was a little more expensive bc of the rear FRPP set.

Josh Main

I wanted to circle back around and thank everyone for the help. I just installed the mustang 4.09 FRPP gears in the rear along with the mustang LSD for the Super 8.8. Everything fit and has been working fine, I just had to thin the C-Clips ten thousandths to get them to fit. It's a tight squeeze. Also, I modified Forscan to run 4.10 gears and it changed the shift patterns perfect. I'm avg about 15 mpg with 6 inch lift and 35's. Highly recommended and woke up the truck.

nodents2017

Sorry to resurrect a 4 year old thread but I’m considering doing this modification and was wondering how the long term reliability is with the gears not being a 1:1 match. Has anyone had issues with using 4.09/4.10 gears? I want to stay with Ford OEM gears but I have a 3.55 rear end. Im not knowledgeable about regearing and I’m not aware of how much the front and rear gears can be off before you run into issues in 4WD.

Josh Main

same reliability as oem