Before removing the side cover to remove any noisy lifters, run the engine with the rocker arm cover off and listen to each valve train combination approximately 1/2” from the pad on the rocker arm using a piece of heater hose to transmit the sound. See Figure 6.
This is a very effective way to pick out which of the 16 lifters is causing the noise.
Whenever the noise is of a clicking nature and not a loud clatter, it is possible to have a cocked valve spring, misaligned guide or sticking valve. Either of these items will emit a noise which is very similar to that of a noisy valve lifter and it is impossible to tell by sound alone whether or not the lifter is at fault. For this reason, it is recommended that pressure be applied to first one side of the valve spring and then the other to see what effect this will have on the noise. Then rotate the valve spring 180° and pour a small amount of light penetrating oil on the valve spring cap. If this has no effect on the noise level the lifter will be at fault in most cases. It is very difficult to differentiate between noisy lifters and eccentric valve seats. A careful valve grind is necessary to eliminate an eccentric seating condition.
After the noisy lifter or lifters are found, mark their position numbers on the cowl with a pencil.