I talked with Tom yesterday about the plug and vent. The presure relief valve is left just as it is, a .060 hole is drilled at an angle into the pickup tube side (probably with the pickup tube in place); the pressure valve opening is then pluged (maybe one of the small drive in freeze plugs or he even suggested silicone.) Careful not to cover the hole you drilled.
The idea being to eliminate air being pulled into the pump through the pressure relief valve as this is supposed to cause hydralic lifter problems
