Differentials can be used "up to" the gear ratio stated and then you need a new gear ratio for the "and higher" ratio.
There are exceptions to these rules in that there are some gears that are made in a "thick" style that will fit the lower ratio carriers (most notably the Dana 44 4.10, 4.56, 4.88, and 5.13 ratios).
AMC 20 - up to 2.73 and 3.08 and higher
Chrysler 7.25" - All ratios
Chrysler 8.25" - up to 2.45 and 2.71 and higher
Chrysler 8.75" Tapered Pinion - All ratios
Chrysler 8.75" Straight Pinion - All ratios
Chrysler 9.25" - All ratios
Chrysler 10.5" - All ratios
Dana 28 - up to 3.45 and 3.73 and higher
Dana 30 - up to 3.54 and 3.73 and higher
Dana 35 - up to 3.31 and 3.54 and higher
Dana 44 - up to 3.73 and 3.92 and higher
Dana 60 - up to 4.10 and 4.56 and higher
Dana 70 - up to 4.10 and 4.56 and higher
Dana 80 - up to 3.73 and 4.10 and higher
Ford 8.8" - All ratios
Ford 9" - All ratios
Ford 9.75" - All ratios
Ford 10.25"/10.5" - All ratios
GM 7.5" (10-bolt) - up to 3.08 and 3.23 and higher
GM 8.5" (10-bolt) - All ratios
GM 8.875" (12-bolt) - All ratios
GM 9.25" IFS - All ratios
GM 9.5" (14-bolt semi-float) - All ratios
GM 10.5" (14-bolt full-float w/removeable pinion support) - up to 4.10 and 4.56 and higher
GM 11.5" (14-bolt full-float w/non-removeable pinion support) - All ratios
Toyota - All ratios