How many miles can you expect to get out of GC's (Around 2001 models) if properly maintained?

I'm in the market for one, but ALL THAT I CAN FIND are what I would think to be very high mileage? 160-180k miles on everything that I can find.

How many miles can these things go for on average?

Is there any major issues with these vans? I know previous models had severe transmission issues.

Any help/info would be greatly appreciated.

 

They all have transmission issues. Last year I put a trans in a 2003 that is used for a delivery service. It has 310,000 miles when the trans finally quit, and now he's at 380,000 miles. No other major issues. My personal van is a 02 t-c with 244,000 with no problems yet.