The truck definitely does not knock ever, even on cold startup. I don't think that the squeaking that I'm hearing is oil related, probably just a loose belt as someone mentioned. The previous owner maintained it religiously to the point of overkill. Oil changes every 2,500 miles on the dot. Gear oil and differential oil changes every few years, etc. The truck runs pretty much like new at 151,000 miles, besides the squeaking issue I have mentioned.

Anyways, I decided to go with the 10w-40 over the 10w-30 because the truck will see at least a couple long distance hauls towing a trailer over the summer time. I may switch over to 10w30 for the winter. Living in California, The truck will never see temperatures cold enough to warrant 5w30.

Like I mentioned in the first post, I have a '73 Ford Country Squire Wagon with the same 460 engine. Carbureted as opposed to Fuel injected, a straight up timing set as opposed to 8deg retarded, and with significantly less emissions controls. But overall, the engine internals are pretty much the same. I have always run 10W-30 in that and sometimes 10w-40 in the summertime. I have never had any problems with that car (now at 121,000 miles), so I think I'll follow that for the truck.