Search by number: 1991 Buick Park Avenue 3.8L 6 Cyl Starter ProAmp 6431 $76.00 each OPTIONS: w/Supercharger ProAmp 16868 $99.00 each OPTIONS: wo/Supercharger, 2.84 Final Drive Ratio ProAmp 6339 $107.00 each OPTIONS: wo/Supercharger, 3.06 Final Drive Ratio ProAmpN 6339N $103.00 each OPTIONS: wo/Supercharger, 3.06 Final Drive Ratio ProAmpN 6431N $113.00 each OPTIONS: w/Supercharger