I am thinking of fitting a set of variable duration / anti pump-up lifters i.e. Rhoads in my Cleveland. Has anyone else fitted them to their motor, and did they make any noticeable difference? For your info, the motor is a 351 Cleveland, 9.5:1 compression, 2V heads, Comp Cams 268H cam, Edelbrock Performer 2V intake, Holley 600 vacuum secondary carb, headers. Motor is in a '71 Torino.