Hey guys, looking at buying a 95-97 pwerstoke to be my daily driver. I have a 150 round trip commute. It's all highway, so I will be ditching the 4.10 gears for some 3.55, my cousin brought up that I should consider 3.31 causemy whole trip is highway.. But my highway is hwy 152 "Pacheco pass", so my question is... Because I daily drive a mountain pass will the 3.31 gears put to much stress on the tranny??

 

Keep the 3.55's

 

2x on 3.55's. If you get 3.31's you'll be hating life if you ever need to tow or haul any kind of a load. Auto or Manual trans?

 

I would go to 3.73 if it were me, with 3.55 you will be at 1500 rpm @ 60mph, fyi.

 

1500 at 60?? Are you sure? Cause my cousin had 4.10 in his (manual trans) and he is at 2300 at 65.... I know te auto has a bigger od gear but I didn't think it was that big of a difference

 

1450 RPM @ 55 MPH in OVERDRIVE.

 

I thought the Auto had like a 0.76:1 ratio in OD and the ZF had like a 0.75:1 ratio in 5th.
Not much difference.

 

There is not a huge difference between the two, but there is enough difference to make a bout 200 RPM more on the ZF at 70. I have driven both and there is definitely a difference, but I don't know exactly what the ratios are. I know my E4OD with 4.10's turns about 2,000 RPM at 70 and the ZF'd truck I am parting out turned about 2,200 RPM at the same speed with the same rear end gears.

 

That sounds about right, my cousin has a ZF with 4.10 gears.