SBC Thick and Thin Oil Pan Gaskets - Which do I need?

Ever ran into the headache of an oil pan gasket that doesn’t quite fit your timing cover? Well, like every problem, we have a solution; or a tip rather, that will save you the extra run to the parts house. On a small block Chevy engine, some oil pan gaskets are a bit thicker than others (about 1/8-inch) and this can cause a problem where the gasket seals inside the timing cover grove. Some timing covers (like Speedway's 910-11040) have a thin groove, and others are thick. Fel-Pro specifies a "thick" oil pan gaskets as measuring 3/8-inch, and a "thin" oil pan gaskets at 1/4-inch. The images below compare the problem found between a thick and thin gasket.

Which oil pans use which gaskets? There is a general guideline. Regardless of the year range, remember to always measure the differences with the examples above. For most applications:

• SBC OEM oil pans made 1955-1974 used a thin seal
• SBC OEM oil pans made in 1975 and later used the thick seal
• Most aftermarket oil pans use the a thick seal

Remember, the correct thick or thin SBC oil pan gasket is important to prevent leaks. It's also important to measure your timing cover width. However, a few quick measurements and our guide will help save a return to the parts store.

In the following images we show how the wrong gasket can cause oil leaks and even oil pan deformation if you attempt to bolt the pan down without confirming the proper gasket is being used. Always check your pan's measurements, or use the oil pan gasket recommended by the aftermarket oil pan manufacturer and you'll only have to do the job once to be leak free!