Since we are talking crawl ratios I noticed no one has talked about axle gearing. A big part of picking axles is going with a set that have a good gear ratio. OR have good aftermarket gear ratio options. But you will save your self some money if you get a set of axles with a decent gear set all ready in them.

Here is the reality you are working with on most Gen 1s (5spds at least, automatics are close):

Transmission 1st Gear (KM145)= 3.967

Transfer Case = 1.944:1

Differentials = 4.625

So your crawl ratio turns out to = 3.967 x 1.944 x 4.625 = 35.67:1

(Keep in mind a good crawl ratio for regular/serious wheeling is usually considered 50:1 and above, better being 100:1 and above)

35.67:1 for a stock truck isn't horrible, but its not the best either. Just think if you get a set of axles with 3.73s in them:

3.967 x 1.944 x 3.73 = 28.76:1

Or lets say 4.10s even:

3.967 x 1.944 x 4.10 = 31.61:1

The way Mitsubishi did it, was they went with a fairly crappy T-Case ratio of 1.944:1 but made up for it in the axles with the 4.62 gears (or 4.88s in some cases). See in Jeeps etc they have a better T-Case ratio, but then put higher (numerically lower) gears in the differentials.

For example the NP231 transfer case that has been used in many Jeeps has a ratio of 2.72:1 . Combine with say 3.73 gears using the 1st gear ratio from a TJ:

3.83 x 2.72 x 3.73 = 38.85:1

So point being, keep an eye on what gears are in the axles you are swapping in. We don't have the T-Case gearing to compensate for higher (numerically lower) gear ratios in the axles.

You could drop 2.85 T-Case gears in for about $1,200, but at the point even with custom fab work I bet it would be cheaper to adapt an NP231 to the KM145/KM148. <img src="/forums/images/graemlins/shiner.gif" alt="" />