[bouncytruck]

I have only heard of 3.07 and 3.73 in [stock] 4wd blazers. One of my previous Blazers had 350/TH350/NP203 combo with 4.10 gears on 35" tires (none of it was stock). It felt like top speed was around 65 (but it was too scary to drive faster than that).

If you have a 10 bolt, I'd double check that your front and rear gearing matches before putting it into 4wd.