best type of oil for 71 340 engine

matthew110366 said

I live in Kentucky , during the summer months it can get to 90 degree plus , but it stays in to mid to high 80s , I only drive the car in the spring and summer mnths only to cruises and shows ... I didn't rebuild the motor and Im unaware of the specs ... So I'm looking for the best combination for the motor.
Regards

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THE most important aspect of modern oil is the removal of zink and other mineral additives. Any flat tappet engine needs those additives to live, wether it is a fresh rebuild or has 100k miles on it and especially if you are running a high lift cam with high seat/spring pressures. I use 10/30 Mobil 5000 and a bottle of ZDDP. You can buy special oils with the additives but it gets spendy in a hurry. I buy the Mobil at Wal-Mart in a 5 quart jug for $11 and a bottle of ZDDP is another $8-10. I currently have 3 classics running on this combo with zero cam wear issues........so far.

Robbie running the Rotella.........they took the zink out of that too because of the particulate filters on the new diesels. Might wanna see if yours is the older stuff that still had it. I run Mobil Super 1300 in my Pete and was told of this a couple years ago by my distributor. He said if I was using the oil in any flat tappet car engines to use an additive or get the special oil...:sad3: