NEW SWS CHEVY ALUMINUM BELLHOUSING, FLYWHEEL INSPECTION COVER, CLUTCH FORK BOOT & CLUTCH PIVOT BALL, GM 621 3899621 REPLACEMENT FOR SBC & BBC FOR 11" MANUAL CLUTCH APPLICATIONS Brand New Southwest Speed Aluminum Bellhousing Kit for 11" Clutches with Manual Transmissions that includes a replica GM 3899621 Bellhousing, Flywheel Inspection Cover, Clutch Fork Pivot Ball, and Clutch Fork Dust Boot. (SWS Part # 650-3975, 650-3968, 650-4018, and 650-3952). This Southwest Speed 11" Performance Cast Aluminum Bellhousing is a reproduction of the original 3899621 bellhousing used on GM models w/Big Block and Small Block engines equipped with an 11" clutch &gt; This performance aluminum bellhousing does not have the GM Part # 3899621 casting number but will look, fit, and perform just like original &gt; If you are doing a restoration of an early muscle car, or just want the correct bellhousing to finish that rod project, this bellhousing is the perfect part Fits: | * 1964 - 1988 Chevy Chevelle, Malibu, Monte Carlo* | * 1959 - 1987 Chevy El Camino* | * 1959 - 1988 Chevy Impala, Caprice, Bel Air, Biscayne, Brookwood, Kingswood, Nomad, Sedan Delivery* | * 1963 - 1981 Chevy Corvette* | * 1967 - 1981 Chevy Camaro* | * 1968 - 1974 Chevy II, Nova* | **With Manual Transmissions and 168 tooth Flywheel The bellhousing was used with 4 speed transmissions in 66-72 Chevelle, 66-81 Corvette, 67-72 Camaro, 68-72 Nova, and 64-81 Impala, but with any GM transmission that measures 4.675" and an 11" clutch &gt; This new Chevy high performance 11" style aluminum bellhousing was issued on Camaros, Chevelles, Impalas, Corvettes and Novas with big block 396, 427, and 454 engines, as well as Yenko, Copo, and ZL1 and also small blocks like 302, 327, 350 and 400 Will accept your original Muncie or Saginaw Manual Transmission with a 4.675" O.D. bearing retainer &gt; Will even work with the Tremec 5 and 6 Speed Transmissions &gt; You can use one of the new bolt-in Classic Car Conversion Transmissions and still use all of the Stock 4 Speed Pedals and Rods with this bellhousing