Search by number: 1991 Buick Park Avenue 3.8L 6 Cyl Starter ProAmp 6431 $72.00 each OPTIONS: w/Supercharger ProAmp 6339 $88.00 each OPTIONS: wo/Supercharger, 3.06 Final Drive Ratio ProAmp 16868 $98.00 each OPTIONS: wo/Supercharger, 2.84 Final Drive Ratio ProAmpN 6339N $95.00 each OPTIONS: wo/Supercharger, 3.06 Final Drive Ratio ProAmpN 6431N $145.00 each OPTIONS: w/Supercharger