general problems of the 2000 Chevrolet K3500

We purchased this Chevrolet dually truck in Nov 00. The two front tires had excessive wear and were replaced by the dealer after two weeks of trying to locate them. We have found that goodyear no longer makes these tires. The truck was mfg 03/00 and the tires have a dot # that indicated the tires were mfg 07/00. We will not be able to obtain replacements should we have a blowout. Understand a class action suit was filed Dec 01 re these tires. Chevrolet customer service has given us the runaround for the last four weeks and refuses to do anything about these defective tires (total of 7 on the truck). I don't believe the truck sat for four months with no tires in the beginning. Also someone needs to do something about the total lack of assistance with chev customer service, no return calls, lack of research and in general, a complete runaround over a period of four weeks. (dot number: mk1l tiresize: 225/75r16).