Holley Engine Block Drill Jig 302-31;

When installing a LS7 with a dry sump system into your project, you will need to modify a few items on the engine before installation of the wet sump system. LS dry sump engines have the dipstick in the remote oil tank. The boss in the block that is typically used for the dipstick is not drilled. When converting to wet sump the boss must be drilled. This boss is parallel to nothing else and you only get one shot at the hole. Holley has developed an easy guide to help locate the bit during the drilling process. Using two nearby threaded block holes, the guide creates easy alignment for a hand drill to exactly drill the hole GM would have for a wet sump application.