To verify camshaft lobe lift and to see how much they have been worn out then the rocker arm covers and rocker arms have to be removed but the pushrods have to remain on. Where the top dead center TDC on the compression stroke and then secure a dial indicator on the engine in a way that the plunger of the indicator rests upon the first pushrod. Rotate the crankshaft until the contact of the dial indicator is broken and then turn the crankshaft in the opposite direction until the tip of the indicator jumps out of scale and take the maximal cam lobe lift. With this figure recorded reposition the piston at TDC then move the dial indicator to the next pushrod and do the check over the other valves and remember it is cylinder to cylinder, firing order wise. After the checks are done, compare the readings with the specifications; when camshaft lobe lift figure is lower than the specified value, one gets to see that the engine has worn out and therefore is expected to replace the camshaft. For removal, removal of pushrods, valve lifters, timing chain as well as the camshaft sprocket before checking the V8 engine camshaft end play with the aid of a dial indicator as well as replacement of the thrust plate if needed. Slowly and gently lift the camshaft out and be sure to steady it in order not to harm the bearings. For inspection, it is recommended to follow the procedure for the camshaft and the bearings inspection together with the roller and the conventional lifters' inspection. Bearings head of camshaft can be replaced only with special tools and should be done only at an automotive machine workshop. For installation, drop the camshaft lubing its bearing journals and lobes, slid the camshaft into the engine while supporting it, apply grease to the thrust plate, place the thrust plate at the block prior to tightening the bolts. Lastly fit the lifters, pushrods, rocker arms, timing chain/sprocket, timing chain cover and the rocker arm covers in the reverse manner you removed them and the last step is to change the oil with a new filter before starting the engine.
