Includes: (16) #4610-W FS/FW Washer, #4610-N FS/FW 5/16" Adjusting Nut. Many of the popular engine families utilize a positive stop type of Rocker arm attachment, which does not allow for any adjustment and consequently there is no consideration for different Cam sizes or other modifications to the engine block and heads. For that reason, COMP has designed a kit to convert this setup to a fully adjustable valve train. On the 302-351W Fords, simply remove the standard adjusting nut, slip the spacer over the Stud, install the new nut and adjust the valves as necessary. On the Mark V and VI Big Block Chevrolet engines, replace the screw-in Studs with those provided, slip the spacer insert through the Rocker arm ball, and adjust with the new adjusting nut. These kits are a simple and inexpensive alternative to give the flexibility of an adjustable valve train.