List of GM bellhousing patterns
Chevrolet V8 pattern
So named because it began with Chevrolet's V8 engines.
- Chevrolet big-block V8's
- Chevrolet small-block V8's
- GM Vortec 4300 90° V6
- GM Iron Duke RWD inline 4 (Early RWD Variants, later versions may use a FWD pattern, and have two possible starter locations)
- Jeep with GM Iron Duke inline 4 2.5L/151 in³ (1980-1983). These use a Chrysler custom Torqueflite 904 automatic transmission with an integral Chevrolet bellhousing. Do not confuse with later AMC 2.5 L engine that uses GM small corporate pattern (see below).
- Chevrolet Inline 6 (post-1962)
- Chevrolet 153 Inline 4 (Chevy II, pre-Iron-Duke - includes the Vortec 3000/181 industrial/marine crate motor)
- GM Atlas engine
- Detroit Diesel 6.2/6.5L V8
- Duramax V8
GM metric pattern
- Also called the GM small corporate pattern and the S10 pattern
This pattern has a distinctive odd-sided hexagonal shape. Rear wheel drive applications have the starter mounted on the right side of the block (when viewed from the flywheel) and on the opposite side of the block than front wheel drive. The 2.2l S10/Sonoma had the starter located in the same position as front wheel drive cars. A rear wheel drive bellhousing is displayed at right.
- GM 2.8/3.1/3.4/3.5/3.9 L V6 (also used by AMC)
- Buick 3300/3800 V6
- Cadillac 4.1/4.5/4.9 L V8
- Isuzu 3.5L DOHC V6
- AMC/Chrysler 2.5L I4 found in Jeep Cherokee, Comanche, Wagoneer, CJ and Wrangler and Dodge Dakota
- GM Iron Duke/Tech-4 2.5L I4
- GM "122" 1.8/2.0/2.2 L I4
- GM 5.3L LS4 V8
- GM 3.5L LX5 "Short Star" V6
Nearly identical to the GM small corporate/metric pattern, except that the starter is located between the cylinder banks, and the lower right bolt hole is moved outward by roughly one inch. Being nearly identical, it too has the distinctive odd-sided hexagonal shape. These engines can be fitted in Rear Wheel Drive vehicles with the right bellhousing and are used in hot rods, kit cars, sand rails and late model engine swaps.
Pre 1964 Buick and Rover V-8 Round pattern
Buick, Oldsmobile, Pontiac (BOP) V8 pattern
- Post-1965 Buick/Oldsmobile/Pontiac RWD V8's
- Buick Big Block's and post-1963 Small Block V8's
- Buick pre-3800 90° RWD V6's
- Jeep "Dauntless" 225 in³ oddfire V6 (1967-1974) and Buick 350 V8 (1969-1970)
- Cadillac cast iron V8s after 1967 (1968-85 472 and 500, 368 and 425)
- Starters are on the left (drivers) side on Olds 350-455 and Pontiac and the right (passenger) side on Cadillac 425/472/500 and Buick 225/231/3800/300/340/350/400/430/455.
Cadillac V8 pattern, pre-1967
Early Cadillacs manufactured before 1965 used a "round top" bellhousing very similar to early Buicks; around 1965, the bellhousing pattern was revised until the BOP bolt pattern was adopted in 1968.