Chevrolet's small-block 350 engine was first used in 1968, and immediately became its most popular small-block. The majority of 350 engines were produced with hydraulic lifters because they were relatively maintenance free and operated quietly, which made them better suited for street operation, rather than for racing applications. Solid lifters, by contrast, require periodic adjustment and produce an audible tapping sound, but are better suited for high engine speeds. Adjusting solid lifters in a 350 is fairly simple, but can take an hour or more to complete.
Locate the number one cylinder and the intake and exhaust valves. The number one cylinder is on the driver's side of the engine, closest to the front. Each cylinder uses two valves, which are controlled by a pair of rocker arms. The rocker arm on the left of each pair controls the exhaust valve, while the rocker arm on the right controls the intake valve.
Turn the engine with a wrench until the rocker arm above the number one cylinder's exhaust valve begins to push down on the tip of the valve. The rocker arm has two ends. One end is pushed upward by the pushrod, while the other end of the rocker arm pushes down on the top of the valve. The engine can be turned by turning the bolt in the center of the harmonic balancer with a wrench.
Loosen the nut located in the center of the rocker arm for the intake valve until the pushrod underneath the rocker arm can be twisted with the thumb and first finger. Insert the blade of a feeler gauge between the tip of the rocker arm and the top of the valve. A feeler gauge has several different blades, each of a different thickness. Use the blade that is .016 inch thick.
Turn the nut in the center of the rocker arm until the feeler gauge fits securely between the tip of the rocker arm and the top of the valve, then remove the feeler gauge to complete the adjustment for that valve.
Turn engine with a wrench until the rocker arm above the number one cylinder's intake valve begins to push down on the tip of the valve. Loosen the nut located in the center of the rocker arm for the exhaust valve until the pushrod underneath the rocker arm can be twisted. Insert the blade of a feeler gauge between the tip of the rocker arm and the top of the valve. Use the blade that is .018 inch thick for the exhaust valve. Turn the nut in the center of the rocker arm until the feeler gauge fits securely between the tip of the rocker arm and the top of the valve, then remove the feeler gauge to complete the adjustment for the exhaust valve.
Repeat the process for each valve for the remaining cylinders on the driver's side of the engine, then adjust the valves on the passenger's side of the engine using the same method to complete the process.
