31 spline swap new gear ratio choice

Lwiss · Mar 23, 2011

Hello,
id like to swap my axles to 31 splines, and change the gears at the same time as the differential,

i have 3.73s on there right now and id like to run 26 inch slicks after the swap, i cant really decide between 3.73 3.90 4.10, my goal is to run high 12s,

i have a little over 300whp what ratio do you guys think would be the best, I dont care about the gas mileage or rpm on highway but wouldnt really want to go higher than 4.10 because the car is still driven on the streets with 245/50R16 tires
i would go over 4.10 if it was necessary to be able to run 12s.

MustangChris · Mar 23, 2011

what are your cars modifications? Turbo/centrifical blower will have an ideal gear ratio, whereas N/A and top-mount may have another...

Win · Mar 23, 2011

as said in the past, there are many people that have run 28spline with a stock rear end in the 11's and into the 10's.

If your really worried just get some Hardened 28 spline axles. Otherwise save your money and get a Detroit Tru Trac with Moser 31 spline and choose your gears.

Lwiss · Mar 23, 2011

Win said:
as said in the past, there are many people that have run 28spline with a stock rear end in the 11's and into the 10's.

If your really worried just get some Hardened 28 spline axles. Otherwise save your money and get a Detroit Tru Trac with Moser 31 spline and choose your gears.

Thats a good idea, i never thought about that one

Lwiss · Mar 23, 2011

MustangChris said:
what are your cars modifications? Turbo/centrifical blower will have an ideal gear ratio, whereas N/A and top-mount may have another...

the car is n/a its an HCI 302