ghostrider

Anybody have any first hand knowledge of an auburn pro diff on the street?

I have a 98 f150 2wd, 5 speed, with a 8.8 rear. The diff and gears I have are stock open diff with 3.55's and I want to take advantage of the motor I built last year currently n/a putting 308 to the rear wheels.
The truck is driven about 10k a year and see's the 1/4 mile a few times a year. Tires are 295/45/18's.
Any advice is welcomed here, even smart *** comments. I'm also looking to re-gear with either 4.10's or 4.30's any thoughts guys?

Carcrazygts2

The mod motors love gear. I was running 4.30's in my 98 cobra. I would go with 4.10's. I had a auburn pro in my cobra. It lock all the time but was tough for me to drive smoothly. I would look into a Detroit truetrac. It will lock at the strip, and will be easy to drive on the street.

ghostrider

The reason I am thinking about the auburn is that a local guy has one for 175 probably get it for 150ish.
The true trac would be nice but isn't in the budget. If I don't get the auburn pro I'll probably just get a 03-04 cobra LSD with the carbon clutches.

Dholla

I would go 4:10's if i was you, that's what im running with my truck and they are good for fuel mileage and to add a little better performance

ghostrider

I wonder what the rpm difference in the 4.10's and 4.30's is at 70mph??? Anybody

4x4Dustin

There is a free app on the iPhone called "Randy's Gear Calculator" it has an rpm calculator that was spot on in my truck and I believe you should be able to go to Randy's ring and pinion's website and it should be on there also!

FordmanUGA

Weird, couldn't find that app, no matches.

ghostrider

Looks like at 70 there is only about 160ish rpm difference in the 4.30's and 4.10's

4x4Dustin

Try "Gear tool kit"

FordmanUGA

Found it, thanks.