I belive you can only go 10 percent on the differnet ratios. Like 4.10 and 4.09, or 3.40 and 3.42, or 3.70 and 3.73. Hope that helps. You could get away with more if you only used 4 wheel drive in heavy mud where there is no traction. If you used say 4.10 in the rear and 3.73 up front and used it on hard packed dirt you will destroy the transfer case very quickly.
86 Jimmy 4"lift 35"MTRs locked front.Other cars 69 Firebird w/525 hp,and 70 GTO <a target="_blank" href=http://www.geocities.com/modifierperformance>MY vehicles</a>