You can cut the road draft tube off, weld up the hole, and fit the can-shaped part that plugs into the block with a rubber grommet to accept a PCV valve. Don't try the fix of putting a shallow-lip freeze plug into the block with a PCV fitted into it- - - -the valve will suck up oil from the crankcase as well as vapors. You'll need a vent of some sort in the valve cover area, such as an oil filler cap with a mesh screen vent built in, or a clean-air inlet that draws air from the clean side of the air filter. (best choice) The PCV will need a 3/8" diameter hose connected directly to the intake manifold, and you'll need to adjust the idle speed and mixture to compensate for the increased airflow into the engine. The engine will last a lot longer, due to the more efficient removal of corrosive crankcase vapors, and less dust and dirt pulled into the cramkcase by the open vent system.
Jerry
