Been looking at a GMC 3500 crew cab dually with the 6.6 however the last recorded odometer reading is 307000+. I keep reading this is the year model Duramax to have but is the mileage way too high? Should I just keep on looking? What sort of things should I look for?
Thanks for any advice.

 

Seems fine to me! Mine blew a head gasket at 298k otherwise was great.

I suggest a lift pump, fuel rail shims, and egr delete. Leave the HP low/stockish and enjoy the reliability

 

300k miles is a lot, but if it was well maintained it should be okay, I wouldn't expect it to last for a long time, but who knows, if it were me, I would be looking for under 200k miles....

heck mines got less than 150k miles