1929-1934 Rocker Shafts & Bushing Kits
Chevrolet did not offer separate bushings for rocker arms after 1931. The reason for this was that the bushings for 1932 were so thin that they must be installed in the rocker arm BEFORE the oil groove was cut into the bushing. None of the reproduction rocker arm bushings come with oil grooves. As part of the installation of these bushings, a groove must be cut into the center of the bushing for oil flow to the weep hole at the top of the rocker arm. Failure to do this will cause a lack of oil at the valve stem or pushrod tip.
After removing the original bushings, press in the new bushings into the rocker arms. Once the bushings are installed, drill a hole through the bushing, using the weep hole as a guide. Drill the hole the same size as the weep hole. Note: 1929-31 models use an oil wick to feed oil to the pushrod tip. Replace these wicks when rebuilding the rocker arm assemblies.
The next step is to cut a shallow groove in the bushing, all around the center of the bushing. One method to do this is using a Dremel tool with a flat grinding disk. Cut most of the way through the bushing but try not to go all the way through. The groove needs to be at least the width of the oil weep hole, but slightly wider won't hurt.
Once the groove is cut 364912 1929-33 Valve Springs all around the center of the bushing, use emery cloth to remove any rough edges. Fit the rocker arms to the shafts. Be sure to oil all bushing surfaces prior to assembly.
1932-34 rocker shafts may have shouldered bolts holding the rocker shafts to the rocker stands. There are four of these bolts. The shafts we provide will not allow for a shouldered bolt, so these must be changed. These are not a hardened bolt, so you should be able to go to an auto parts or hardware store and purchase bolts with no shoulder.
CAUTION: When installing 1932-34 rocker arm shafts, you must INSURE THAT THE OIL HOLES ARE ON THE BOTTOM. Failure to do this will cause poor oiling to the bushings and therefore, premature failure of the bushings. (Note: 1929-31 rocker shafts have oil holes at the top and bottom).
Check the rocker arm adjusting screws when rebuilding the rocker arms. Remove each adjusting stud completely. Check the threads carefully as these can break off and cause the adjuster to lock or move at the wrong time.
One last check would be to inspect the tip of the rocker arm where it meets the top of the valve. This is a common wear area. If there is "cupping" at the tip, it must be resurfaced until it is smooth. In extreme cases it will be necessary to build up the tip of the rocker by welding with a hard material like Stellite. A machine shop can then grind the tip smooth while keeping it slightly rounded.