S&S, Shovel tappet guides for Evo tappets

Polished. When retro-fitting these billet aluminum tappet blocks to a Shovel engine you must use 86-99 Evolution Big Twin hydraulic lifters, an Evo style camshaft and S&S Quickee pushrods. If desired you can oil the top end through the pushrods (with 512497 Quickee pushrods), Evolution style, when using S&S Shovel roller rockers (512493). Note that an Evo cam will have about 8% reduction in valve lift due to the lower S&S Shovelhead rocker arm ratio (1.5), when compared to the stock Evo rocker arm ratio (1.625). The stock rocker arm ratio of Shovelhead rockers is 1.43. Note: Adjuistable pushrods are required. Note: 512511 pushrod 'clips' are required when using 512494 Evo style tappet blocks for Shovel. Since these tappet blocks are longer a shorter clip is required for correct pushrod cover spring tension. Fits: > 66-84 SHOVEL(NU) MUST USE: EVO TAPPETS & EVO CAM & S&S QUICKEE PUSHRODS FOR EASY-INSTALL