Recommended motor oil weight for 440 6-pack?

[JDS-70R/T]

Can you guys recommend the best motor oil weight for my 440 six pack. Not sure if the motor has been rebuilt or if it has over 3500 miles since a rebuild so I would need to stay away from synthetics. I have been told to use a good 10-30 or 10-40. The engine is pretty much stock and not used for racing other than occasionally getting on it. Thoughts?

 

[Dennis H]

My builder (Mopar Engines West) recommends synthetic after brief break in. Amsoil Signature 10-40. High Zinc. Been hammering the 440 for over 35 thousand miles. No leaks or consumption.

 

[Meep-Meep]

Yep, good oil with the additive package consistent with API SL or lower is what you want. I use 15-40 SWEPCO. Synthetic is OK to use too.

 

[JDS-70R/T]

thanks

 

[themechanic]

Depends on how cold it gets in Iowa in the winter. Here in Oklahoma I use 10W40 Brad Penn. It is a synthetic blend with lots of flat tappet goodness.

In the Lubrication and Maintenance section of a Service Manual it says to use 10W30 and 10W40 in most of the US where temps occasionally dip to -10 degrees F.

 

[moparcanuck]

Brad Penn 10-40.