new oil for old cars

[wtd]

The last time I changed the oil in my 70 Monte Carlo with a 396 BB in it, I used a ZDDP additive to the oil. I run a 10W-40 in it because even though the engine has been rebuilt, it runs pretty low oil pressure at a hot idle with 10W-30. I think I have conventional Valvoline 10W-40 in it now. I don't drive this car hardly at all so the oil change is a couple of years old now.

Wayne

 

[Zaedock]

Here we go with the ZDDP....

No need for anything special in these applications. Running any form of a 50 weight is absolutely unnecessary. I have rebuilt every one them. Unless you have oil pressure issues, Defy 5W30 will be far superior to any lubricant these engines ever came with.

 

[riggaz]

What are the manufacturer specified oil pressure readings supposed to be vs what you are experiencing? Defo should be 10w-30 in those engines for all temps.