How hard is it to change ratios in an 8-3/4"?

Bill Crowell, I have bought two different carriers (“chunks”) for my 8 3/4 that is in my Duster. Currently it has a 3:23 ratio in it. Now I have 3:55 and 3:91 carriers available. Changing them out takes a couple of hours or a day depending on equipment such as jack stands, ramps, or hoist.

I have considered the purchase of an overdrive unit but right now I don’t want to modify the trans tunnel. The older I get the more attractive the OD unit becomes because I have less desire to wrench on heavy stuff like the carrier units.