Mobil 1 15 W 50

[Speedbird]

Old oil post brought to life?
The eternal question.
What oil?
OP seems to ask about a simple 440 engine.
Mobil One is fine for a daily driver stock MOPAR flat tappet engine.
Thousands and thousands of miles of experience with Mobil One in several cars.
It may be fine for anything else as well.
I've migrated to their "High Mileage" oil with the seal conditioners.
That's how long I've been running it.
A few Simple Rules of Oil.
Get as narrow a range of viscosity as you can for your conditons.
More oil and less additives to increase the viscosity range.
Diesel oil has too much detergent.
Racing oil doesn't have any (or enough) to keep dirt suspended for the filter.
Change that more often.

 

[AR67GTX]

I go back and forth between Rotella and Driven HR oil depending on what I feel the viscosity needs of the engine are. The 15W-40 Rotella weight works well in many engines. Most of the reports I’ve read over the years endorse it for older, flat tappet cam motors. I have a stroked, built 428 Ford, a couple Mopars (440/426) and a built 427 Chevy - all flat tappet. I don’t use synthetic - waste of money to me on cars that at most get 1 or 2 thousand miles a year on them.

 

[casey henson]

Yes...I have been running it in my 400.