This is the only thing I have left from my parts list, it's brand new never used in it's original package for 2008-14 WRX/STI and I bought it for $340.00 and willing to take any reasonable offer.
This GFB Pulley Kit comes with the crank, alternator and power steering pulleys as well as the belt needed for install. Having large heavy pulleys spinning takes away power that is better spent moving the car. This kit takes care of that by replacing the crank pulley with a lighter version that underdrives the power steering and alternator yet leaves the A/C compressor spinning at normal speeds.
Stock Crank Pulley : 5.51lb (STI) / 4.63lb (WRX)
GFB Crank Pulley : .86lb
Stock Power Steering Pulley : .81lb
GFB Power Steering Pulley : .37lb
Stock Alternator Pulley : .36lb
GFB Alternator Pulley : .14lb
Total Mass for GFB Pulley Kit : 1.38lb
Total Mass for Stock Pulleys : 6.69lb (STI) / 5.81lb (WRX)
Mass Savings : 5.31lb (STI) / 4.43lb (WRX)