Hey guys,

I am starting to tear down the rear end of my 67 coupe. I found last night that I have 28 spline small bearing axles.

Current Set-up

• 450HP (crank)
• Open diff, 3.25 gears (pretty worn)
• 28 spline small bearing axle
• 9" housing

Planned Set-Up

• Truetrac Diff
• 3.5 gears
• Same 9" housing
• 31 spline axle?

Is it advised to go to a 31 spline axle at this point based on the change to the 3.5 gears, and the engine output? The 28 spline...

28 vs 31 Spine Axle Question