On engines that use pushrods, rocker arms are levers responsible for transfer up-and-down motion from the camshaft (via the lifters and pushrods) to the valves. Overhead-camshaft engines typically use cam followers, which are similar in function but ride directly on the camshaft lobe. Note that not all -- or even most -- engines use a set rocker arm torque; only those that use shaft rockers -- such as many old Chrysler engines -- rocker through-bolts -- as many Ford V8 engines do -- and a handful of overhead-cam engines use a set rocker bolt torque.
Torque the rocker bolts to 19 foot-pounds for AMC 2.5-liter (150 cubic inch) inline four engines, all engines in the 242 ci inline six-cylinder family and all engines in the 304 V8 family.
Most Ford V8s (and a few V6s) in the Windsor, Cleveland, Boss and "M" families use rocker through bolts, which you should torque to 20 foot-pounds regardless of displacement. Ford FE-series V8s such as the 360, 390, 427 and 428 also use through-bolts; torque them to 42 foot-pounds.
Of all of GM's divisions, only Cadillac made a habit of using shaft rocker systems on its bespoke V8 engines. Torque Cadillac 368, 425, 470 and 500 shaft-to-head bolts to 55 foot-pounds. Pontiac big blocks such as the 455 and small block engines such as the 350, 201 and 326 require 20 foot-pounds on the rocker-to-rocker-stud bolts, as does the 400 Chevrolet small block. Many LS-Series small blocks use shaft rocker systems; torque the shaft-to-head-bolts to 25 foot-pounds. Torque Iron Duke 2.5 inline-six bolts to 20 foot-pounds and Vortec 2.2-liter inline four bolts to 21.
Many of Chrysler's LA-Series engines including the 318, 340, 360 and some of its Magnum-series V10, V8 and V6 evolutions can use shaft rocker systems; torque them to 30 foot-pounds. Torque B and RB-Series engines such as the 400 and 440 to 25 foot-pounds. Torque Chrysler 3.9-liter V6 engines and all in their family to 16.67 foot-pounds, and 2.0-liter four cylinder shaft-to-head bolts to 21 foot-pounds.
Porsche 2.0-liter, 3.0-liter and 3.2-liter flat-six engines use shaft rocker systems; torque their rocker-shaft-to-camshaft-housing bolts to 13.27 foot-pounds.
