What is considered good milage? How many miles could the van start having problems or be considered bad?

Too many variables ...sorry. Past maintenance mostly...unpredictable future.

Its motor was changed at. 75,0000 miles is That good?

And it has 165000 miles now..The man is selling it for $3000.. is that a good buy?

I think you mean 75,000. No, an engine should go farther than that. Much father, that's about half of an engine life, if the engine that was put in then was a used one..then still all the more unpredictable, But if it was rebuilt and done so properly and maintained, it should go well over 100,000. Unfortunately, my opinion anyway, Chrysler products are inferior.

Is inferior good or bad?

About right...NO MORE though...do not pay more than $3k. Make an offer of $2500 and if you have cash, flash it. Carefully, don't be alone, but show him some cash and say "I have $2500 right now. But I am going to have it checked by a mechanic first" and do so

Its a mechanic who is selling the van. He wanted 3500 for it and I offered $3000.

Inferior is Bad. $3500 is too much. I have looked at several sources. Get a CARFAX. Important to do that

Ok ill be sure to do that. THANK YOU SOOOO MUCH

My pleasure. you're welcome