5.0 MPG

A buddy of mine has some 01 Mustang 3.90 gears and has offered to sell to me for cheap, my question is will these work in my 91? I think his rear end is 8.8 also or at least he says it is.

2 kwik

pass..a new set is like 140..they will work but what you'll pay to install them to the same pattern might not be worth it

7upedition

they both have 8.8" rear end so yes they will work, is your car automatic or 5spd?

5.0 MPG

automatic

is there a difference between automatic and standard gears?

92hatchLX

They don't make the gears in automatic or standard. He was just wondering because the AODs have numerically lower gearing than the 5 spds and you tend to want to use a numerically higher gear ratio in the rear end to make up for that. I've got 3.90s and my car has an AOD and they work great. I'd reccomend them.