3.55 Stock to 4.10

[Emperior]

I spoke to a Ford Tech in reference to changing over from 3.55 to 4.10. The Tech stated that changing over would increase speedometer around five miles per hour, increase mileage and affect transmission. Is this true? Alot of MM's are 4.10 now.

[Pops]

This can all be adjusted with a tuner. Get the tuner and tune and have the gears put in. You will like it!

[freakstatus]

The tuners on this site (Reinhart and Alternative) already have 4.10 tunes ready to go! Just call them.

[Bradley G]

I agree, except for the mileage.
When your two ton + barge feels like it went on a diet(4:10's & tune), it's difficult to lay off the go pedal.

[SC Cheesehead]

I agree, except for the mileage.
When your two ton + barge feels like it went on a diet(4:10's & tune), it's difficult to lay off the go pedal.

I agree with Bradley G. Minimal impact on mileage (for me, less than 1 mpg ave "before and after"), but it gets more difficult to keep your foot out of it, so mileage may suffer a bit if you're unable to show restraint.:D

FWIW, running 75 mph on the highway nets me an average 22 mpg.