i have another 77 blazer.its got 35's and 4" susp. and 3" body. The rear end is stock 12bolt with stock gears and 10bolt upfront with same.i really want to upgrade the gears to 4.10's or 4.56's. its gonna be my street truck, and i want it to have good lowend torque. i know nothing about switching gears. How much will a gear place charge me to put in 4.56's in the back? Or should i just get a 14bolt with 4.10's from a junkyard. How much wil that cost to buy and install. Im clueless!