So I just recently purchased an 03 mach 1 automatic that was bone stock when I bought it. I have already done simple mods and i wanted to do gears next but I'm not sure which direction to go on the gears 4:10 or 3:73? Keep in mind it's an automatic daily driver and the last thing I want to do is screw up my tranny!

 

4.10's 100%

 

4.10 all day everyday

 

I want to do 4:10s my only concern is the car has over 100k on it and I don't to damage anything buy running the higher rpms the 4:10s are going to do, but I'm sure with a good tune it should be fine. I'm new to the modding thing so I have alot to learn

 

If your really concerned then just go with 3.73s either way are good