What oil/oil filter are you guys running in your stock 340's?

Thanks for the heads up my man
You're welcome.
Take a look at this. Lake Speed Jr gives a lot of good information you don't need to be a chemist to understand. You can find a lot of his work out there. He'll be selling sometimes, but not too hard, and I've never found him to be deceptive.
All about oil: Lake Speed Jr breaks it down — The Motorhood