Appreciate the info. Ill talk with the builder to see specifically what he suggests weight wise. 5w30 as the factory manual suggests just sounds too thin to me on a big engine, and I like the sound of 10x40 or 15w40.
Sweepleader, with your extensive experience up here in the cold, any suggesting on block warmer? I install and run them on the newer Silverados, but I opt for OEM. Kats heaters just don't seem to have a lot of good reviews. There is Zerostart as well, but there's almost no reviews anywhere. One thing I did see was installing 2 block heaters in the event that one fails you have a backup before you have to drain the coolant and replace. I figure ill install the heaters now wile the engine is on the stand and frost plugs are easy to punch out. Just not sure which route to take.