Well, the LE3.91 gears avg $250, about $150 for bearings and shims. That price sounds high for the labor. Takes appx 1 hour to remove the center section, another hour to install, plus the time to setup the rear. Should be able to be done in a 4 hour window. Dont let them charge u GM book labor time.
I should add, i plan to pull mine back out Monday and put a Eaton Truetrac in it. I plan to be around $1300 including the TrueTrac which cost me $585, new replacement 3.91, new bearings, shims, and labor.
2012: Vmax TBody, CAI w/scoop, Solo HFC, ZL1 FP, Magnaflow TruX, Dynomax VT, RX catch can, Trifecta Tune, BMR; Springs, Sways, Trailing Arms, Toe Ends, & Safety Loop, Pioneer Z150bh, Phoenix Gold Sub, Hertz speakers & 5ch Amp, SS rear with 3.91 gears w/Eaton TrueTrac, and BMR bushings, Baer Decela Rotors, Goodridge brake lines, Brembo(GM) 4 piston calipers, Hawk Ceramic pads, and Vredestein Ultrac Sessanta Tires, Ny-Trex Nitrous, and more. 345RWHP/354lbsTQ