9" versus 9.3" rear axle

[49FordF1]

Other than the obvious .3, what is the difference between the two, or are they the same?

[Hawkrod]

They are similar but different. The 9 3/8 is a 9 inch on steroids. It uses the same axle housing but the housings have to be notched to allow the gears to enter and the 9 3/8 all came with 31 spline axles while the 9 inch can be 28 or 31 spline. The 9 3/8 is heavier duty and was designed for higher torque loads but they never had much of a gear ratio selection so they tend to be unpopular. Hawkrod

[49FordF1]

Thank's for the reply. This is good to know. On the tag it states the 9.3 is a 3L50 which works good for my purposes.

[BobbyFord]

Thank's for the reply. This is good to know. On the tag it states the 9.3 is a 3L50 which works good for my purposes.

3L50, 9 3/8" is what came stock in my truck. It's a nice all around ratio.