I have a 1994 7.4 Turbo deisel with 178,000 miles. I'm begining to get some blowby around my rings. Can I use a product such as Slick 50 or Duralube on a deisel?

 

Yes, but I don't know why you would.

one of that stuff has ever been shown to do any good.

Numerous independent labs have tested. Briggs & Stratton, GM, etc. Never found any benefit.

Just wasted $$$.

 

MY dad actually had to fix a 3.0 horse briggs that a SLick 50 rep locked up, forgot to poor in the oil and slick 50, dad freed her up and sent him on his way.
I used DuraLube on my 82 E350 when the bearings started knocking. Worked great, stock the knock on startup. Even my dad was impressed and he doesn't like these so-called snake-oils.

 

It sounds to me like your '94 wasn't taken care of too well with timely oil changes.. I would add a quart when needed of good oil rather than use some "snake oil" with questionable results....These engines aren't cheap to replace...