The standard ratios would be 3.91:1 in the front, 3.90:1 in the rear. While the front has plenty f available ratios to choose from (Spicer/Dana 44, still in use today in Jeeps), the rear only had a 3.38 ratio as an option, and that may have been a 2wd only option. The 3.38 is the only gear currently being made for the rear.
You are also in the same situation for a limited slip in the rear, they were only made for 3 years for that differential, and are very rare.
Since you ask about limited slip differentials, I take it you plan on possibly doing some off roading with this truck? If so, you may consider swapping in a set of axles from a '73-'87 GM truck, which gets you several advantages. One is the open knuckle front axle, which will be either a Dana 44 or 8.5 ten bolt, depending on year (1/2 and 3/4 ton, 1 ton used a Dana 60). The open knuckle front gets you a stronger spindle, as well as a tighter turning radius. Ratios can range from 3.08 (not recommended) to 4.56. For the rear, you would be looking at the 8.875 12 bolt Truck or 8.5 10 bolt, depending on year, or 110.5 14 bolt if you go with 3/4 ton parts. any of those rears will be much easier to get parts for, any gear you want, plus several types of lockers and limited slip differentials.
