I have a daily driver and I'm considering installing 373s. I would get a tune to recalibrate the speedometer, but what I'm wondering is will this hurt my car in the long run (or at all for that matter)? I know it may cause me to drive faster which may not help engine life, but do gears cause any damage to my car? I have an automatic gt. let me know what you guys know. Thanks

 

I have an auto trans but am running 4:10's. They will not hurt your car just you gas mileage a little bit. 1-2 mpg max. I debated for over a year to go with the 3:73's or the 4:10's. The 4:10's is the right choice most will agree.

 

Yeah, they wont hurt your car. But mine is a dd as well and probably this summer I want to install either 3.73 or 4.10s. Not sure what's the best way to go. Also, not trying to hijack your thread but how much does it cost to put gears in? I know this isn't a task for myself so I would need a mechanic to do it.

 

I bought 3.73's from Ford Racing for $179.95, a deluxe installation kit for $109.95 and bought three qts. Of Royal Purple gear oil and my buddy charged me $300 for the install. I had other shops tell me $600 but they had no idea what brand of gears they used

 

Mine came stock w/ 3.73's. Not going to hurt a thing.