5.13's... as long as you remember you can only use 4wd in slow speed offroad / very slippery situations. (unless you get a matching 5.13 rear axle). The mismatched gear ratio's will bind up your driveline....
I'd only go 4.88's if you had a V8...

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