Topic: 67 390 harmonic balencer bolt finish

[preaction]

My 67 engine assembly manual is calling for an "S" finish which is plain, the bolts I have seen from AMK have been P&O I realize AMK is not always right so what has been the going standard.

[Bob Gaines]

My 67 engine assembly manual is calling for an "S" finish which is plain, the bolts I have seen from AMK have been P&O I realize AMK is not always right so what has been the going standard.

Plain unplated is typical. Dark gray heavy zinc phosphate is not. A light zinc phosphate will have about the same appearance and will hold whatever rust preventive oil based product better.