[TomC750]

[QUOTE=tubman;2361877]Sludge coming out is not a bad thing. If anything, I would run detergent oil and do frequent changes. You may be able to clean more crap out of it. Although I agree with "V8 Bob" about running the thinnest oil practicable, I would go with the 10W-40 for an unknown used engine. I wouldn't worry about the sludge clogging up the engine, as detergent oil is designed to keep it in suspension. Just change it more frequently.

The previous owner may have run non-detergent oil, which is not a good idea.[/QUOTE
]I know. I have heard the following more times than I care to mainly referring to Model A's: They were originally designed to use non detergent oil or some similar statement or even marketed as the right oil for a vintage car. Boy oh boy...
And thanks for your advice. I will go with it.