Just for the record My engine blew while on track at a performance driving school and our friends at GM WILL NOT WARRANTY THE ENGINE REPLACEMENT. The warranty language states that they will not cover damage caused while racing or competetive driving. I was not involved in either situation. I was enrolled in a performance driving school that does not teach racing or allow any competition between students. GM refused to review my class enrollment documents, would not inspect my engine or go through its computer info to even find out why or what caused the engine failed. Many dealers told me that I would have been better off if I had lied add told them it happened on the highway. DO NOT TELL GM YOU WERE EVER ON A TRACK! good luck to all others that enjoy track time with their Z's. I understand that they are changing the dry sump to a larger capacity tank for the 09's. Im now considering a Lingenfelter built engine for my GM BLACKBALLED Z06.

GM came out with a service bulletin specifically covering the ZR1, but what is interesting is how they work it in with what they claim is existing GM policy:

"General Motors designed and produced the ZR1 be driven on the roads. While the car is capable of awesome displays of power and speed it was not designed to be "raced". All of the restrictions that are currently in place for all of GM’s products are in place on the ZR1 as well. There are several notations in the warranty booklets that explain that GM may deny warranty coverage if the vehicle or part has failed due to abuse, neglect, improper or insufficient maintenance or modifications not approved by GM. This includes common "upgrades" customers may make such as wheels, tires, suspension, brakes, air induction and engine calibrations. Please ensure this is covered with the owner when the vehicle is delivered. The ZR1 will perform well in a track environment; however, it was not designed, built or sold as a "track car." If an owner elects to use the car in such a manner, it is outside the intent of the warranty as supplied by General Motors and any damage as a result may not be covered by the GM warranty. Explaining this to a customer before the car is sold may prevent misunderstandings later."

In any event, how they can know that the blown engine was "a result" of an arguable racing activity is difficult to fathom if they haven't taken the engine apart to see why it failed.

The Viper motor, although impressive, does not make the power it should with such as huge motor.

Why do companies make dohc conversion for the lsx motors?

And people keep speculating that it will cost more with no physical proof. GM switched from pushrod to DOHC in the V6 Caddy and the cost are relatively the same as previous models. If you have the supply and demand the benefits far out weigh the negative.