Hi, I just picked up a '97 GMC Sierra 1500, short box, regular cab, with th 4.3. It's fine, and in great condition, but the rear gears are 3.08 and I want to change them to 3.42, for towing our small(20ft) trailer, and because we have a lot of steep, but short, hills around these parts. Couple questions:
a) What is involved in re-calibrating the speedometer after the swap?
b) I have found a few diffs in wrecking yards with the right gears, but none are from a '97. What years interchage directly? I want to just change the pinion and entire carrier, not the whole rear end housing...
c) Is there anything else I need to know, or look out for?
thanks!