[Colin’s 65’ Mustang Coupe]

Hey Everybody,

I have a 65 mustang coupe with a 1990 5.0HO EFI Engine and AOD transmission. My rear end has a 4.11 gear ratio. I know that gear ratio affects torque greatly, However I want to know how much torque the car will have with the new rear end. I’m not sure how to calculate this. The 1990 5.0HO is rated at 225HP and 300 ft-lb of torque. What would he the power specs with the 4.11 gears?

 

[Matter]

A change of differential gears will not change the torque or horsepower of the engine at all. What it does change is the torque multiplication of the engine to the rear tires.

 

[rose62]

With that kind of gear, you'll have to make sure you have a solid valvetrain to make use of it. If your motor doesn't like rpm's that gear is going to be a drag.