Fits 1998.5 to 2002 Cummins 24 valve engines equipped with VP44 injection pumps. Includes o-ring to seal against block and stainless hardware. Now comes with baffling built in. Breather ports use -12AN male o-ring boss fitting. Designed to fit drop in or factory flat mushroom tappets. Does not have clearance for aftermarket roller lifters. Allows for computer to be mounted back in stock location.