After 500 miles of operation of the rebuilt engine:

Warm up the engine, and then run it for 30 minutes at operating temperature.

Re-torque the head bolts and the rocker-arm assembly bolts.

Set the valve lash.

Attach a vacuum gauge to the wiper port on the intake manifold. Attach a tachometer, if you have one.

Start the engine and set the idle as close to 500 rpm as you can get it to idle smoothly.

Adjust the carburetor mixture screw to obtain maximum vacuum.

Adjust the distributor timing to maximum vacuum (or, follow the procedure in the Shop Manual).

Adjust the idle to around 2000 rpm. Adjust the timing/distributor to obtain maximum vacuum.

Reduce the idle to around 450-500 rpm (manual transmission) or 400-450 (automatic transmission). Check the mixture adjustment again - maximum vacuum.

http://www.1954advance-design.com/Documents/Adjustment%20of%20valve%20lash.htm

http://chevy.oldcarmanualproject.com/shop/1955truck2/55ctsm0607.htm

http://chevy.oldcarmanualproject.com/shop/1955truck2/55ctsm0620.htm

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.