I got my FRPP 4.10s installed yesterday, picked up the car today. I have the FRPP diff cover with the preloading bolts for the differeential. One of the bolts broke on the preloader portion, but otherwise everything else is great. Mechanic stated he beleived it had been broken for some time since the end of the bolt was rounded. I haven't looked at it yet.

I shopped around town and got labor estimates for $400 to $325. I asked around from people who race who they trusted to get their gears worked on. They recomended a place called Gear Connection. All they do is gears and differential repairs. Picked up the car and drove it. They are absolutely silent. Not a peep. No squeel no moan or humming. The car has only been through a few heat cycles so it needs a few more and then 500 miles and a fluid change. Looking forward to making some passes.

The old gears were 3.55s made by Yukon. Still in like new condition. The mechanic commented on how the gears looked very good.

The differential is a Detroit Locker.

Going from 3.55s to 4.10s should make a big difference at the track.

 

I'd be interested in hearing your thoughts in how much the 4.10s differ from the 3.55s as you get some mileage on them. I'm thinking 4.10s will be my next mod.

 

notable difference between the 3.55 and 4.10. great off the line, and great from a roll.

 

Love my 4.10's, gas mileage loss was minimal for me and worth the change.

 

my 410s are awesome and had great results. Loss of mpg was minimal.

 

I had them before when I was NA and ran off the bottle. I enjoyed them.

I'm hoping to get a 1.5x 60' and then break into the 11.0 range.