I know many people still driving Dodge trucks from teh 90's, and there is no frame rot that I heard of. My current 97 Dakota is finally starting to rust, but the frame is not a concern at all.

Now, my name-sake 79 W150 simply broke in half while driving down the road. The frame rotted due to debris loading between the fuel tank and siderail of teh frame, a common problem for that era of truck.

I live in SE WI.