OK I did what swampcat said removed one plug wire at a time with motor running . the # 1 wire closest to radiator when removed makes knock go away. Will drain pan now.
Have a 49 service manual says to remove an equal # of shims on each side untill the rod will not move by hand,but can be tapped back and forth with a light tap from an 8 pound hammer . then add shims untill it can be snaped back and forth with one hand. _
(49 manual 51 motor should be the same??)
hope I don't make this worse. thanks Bill
