About 8 ounces of Sea Foam in the crankcase, not the fuel tank, will also help free up stuck oil rings if they're contributing to the smoke screen. You can drive the truck while the additive does its job without risking damaging rod and main bearings or the crankshaft, which is why it's a bad idea to put any load on the engine with the Diesel onboard.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!