Fig. 40.3
In 1987 when Chevrolet started using a Roller camshaft they had to control end float on the camshaft See Fig. 40.3 so a design change was made. The roller cam requires a special thrust plate which is secured by screws to the block. The camshaft also takes a different style of drive gear. These camshafts do not interchange with out some work. It is very difficult to install the roller camshaft into the pre 1987 blocks.