Yes, the 2nd t-case is either 1:1 (regular driving) or 2.3, 4, 4.7 or 5.0:1. SO basically, your crawl ratio now, multiplied by one of those number, is your new gear ratios.
Also, you will have alot more gear options.
You can have 4.7 in the front box, and 1:1 in the rear, 1:1 in the front and 2.3 in the rear, or 4.7 in the front and 2.3 in the rear for super low crawling capabilites.

89 4Runner
3" BL, M/T locks, 33"bfg mt, bilstein, Kayline, tubebumper, toyotafiberglass panels
TBI: Elocker,3.4 w/ORS,b+b,S2Sstg2cams,arias pistons,P+P intake,TRDs/c,URDpullies+7th,downey headers,MAPECU2,WEGO WB, SupraMAF,walboro255,stg4clutch, EPaOo2 sim