This composite lifter guide is the same as used on GenIII GM Small blocks, but with mounting holes for use on Gen 1 GM small blocks. The design of the lifter guide makes it possible to remove the camshaft without removing the intake and lifters. There is just enough friction in the guide to hold the lifters in place if the rocker arms are backed off and the camshaft is rotated a full revolution to push the lifters up.
Services one cylinder head. Two are required.