Engine oils.

Hi, for all those who do not know, I have just gotten a 1965 Dodge Dart, with a 225 in. Anyway, I need engine oil for it, and the operators manual says 20W-40 in the hot weather we have here in California. Now, I had a horrible rattle in the engine so I wanted to find a little thicker oil, like 20W-50. But that was easier said than done since most who carries oils have the low viscosity stuff up to maybe 10W-30. So, I ended up with Kendall 20W-50, and hope it will work fine.
The rattling issue is now solved, it was the valves that had way too much clearance, and all of them.

But, I found a list of oils online, and got very puzzled. So, I figured out, why not post the link to the list here and hear what you all say. I must admit I struggle taking the list 100% seriously.

Best Motor Oils - Complete List - Best Synthetic Oil & Filter

What do you guys think, is this "PSI" figures correct, or have someone just been out there having fun ?


Bill