Running Castrol 10W-30 in all of mine 46 - 235
78-350
05-350

Have always used Castrol in all my trucks never had a problem with a failure due to lack of lubrication.

"If it ain't Steel it ain't Real"
"Earth the insane aslyum for the rest of the Universe"
41 1/2-ton, a work in progress
68 Shortbed stepside 327/325hp/700R4