NEW GM THROWOUT BEARING, CLUTCH FORK, CLUTCH FORK BOOT, CLUTCH PIVOT BALL FOR GM 621 3899621 BELLHOUSINGS, REPLACES GM 3892632, 19245400, 3993851, 3729000 Brand New Southwest Speed Clutch Fork, Throwout Bearing, Clutch Fork Boot, and Clutch Fork Pivot Ball Kit that fits the GM 3899621 11" Bellhousing, as well as nearly all GM bellhousings that use both 153 tooth and 168 tooth flywheels and 10 1/2" and 11" clutches (SWS Part # 650-4028, 650-4035, 650-3952, and 650-4018) &gt; This Southwest Speed Clutch Fork, Throwout Bearing, Clutch Fork Boot, and Pivot Ball is a exact replica of the GM OEM parts Kit Includes: | Southwest Speed Clutch Fork with Ball Retaining Spring (# 650-4028) &gt; Replaces GM Part # 3892632 &gt; Exact Replica of the Original &gt; Fits All Models with 10 1/2" or 11" clutches and 153 tooth or 168 tooth Flywheels &gt; Fits All Small Block or Big Block Chevrolet Engines with Manual Transmission only Southwest Speed Throwout Bearing (# 650-4035) &gt; Replaces GM Part # 19245400 &gt; Exact Replica of the original &gt; Designed to effectively reduce friction &gt; Made of high quality materials for long service life Southwest Speed Clutch Fork Boot (# 650-3952) &gt; Replaces GM Part # 3993851 &gt; Exact Replica of the original &gt; Molded from E.P.D.M rubber for a snug fit that will last for years | Southwest Speed Standard Clutch Fork Pivot Ball (# 650-4018) &gt; Replaces GM Part # 3729000 &gt; Installs into bellhousing to support clutch fork &gt; 13/16"-16 Threads, 1 1/2" total length end to end Factory Applications: &gt; 1966 - 1972 Chevy Chevelle, 4 Speed &gt; 1966 - 1981 Chevy Corvette, 4 Speed &gt; 1967 - 1972 Camaro, 4 Speed &gt; 1968 - 1972 Nova, 4 Speed &gt; 1964 - 81 Impala, 4 Speed &gt; Fits all Applications using a 168 tooth Flywheel