I've always just ran 10w-30 and my 440's been fine. Then again I'm running a stock engine. Add in a more aggressive camshaft lobe design and higher spring pressures and all the sudden lubrication is more critical.

As far as thickness goes, 10w-30 is fine so long as you are able to maintain good oil pressure with it. If oil pressure is too low with the 10-30, step up a grade.

Now for lubricant contents, zinc is more crucial to have in a more aggressive than stock setup as well. I hear people adding in a bottle of the red STP, GM's EOS or whatever they call their newest forumula of it, and other products that are heavy in ZDDP to provide proper camshaft protection with newer oils.

The diesel oils are supposed to have more zinc in them, but I have a hard time finding them in anything thinner than 15w-40, and that's too thick for me.