Respectfully and humbly,
I would suggest interested readers please carefully read the information at the following link before you dump ZDDP additives in your oil: Motor Oil Wear Protection
For the average 351C (excepting those specifically machined to utilize 0W or 5W oil) I recommend Valvoline VR1 (10W30, 10W40 or 20W50), conventional or synthetic, using no additives. After you read the link I believe you'll understand why.
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