My friend has two 472 Hemi engines, and after the Cummins related issues they had (and there were many of them )were sorted out, they have been trouble free. He takes them on Power tours,and road courses. When I bought my Mopar Performance crate Hemi engine in 2005,Comp Cams had sent Cummins a batch of improperly hardened camshafts. My friends second 472 Hemi lunched one of those cams after six hours of run time. It was a new engine, and Cummins rebuilt it under the warranty. My engine may have one of those cams,so I have never run the engine. No one is going to honor the warranty on an engine I bought in 2005,and never ran. I bought new cam and lifters from Indy Cylinder Head,that was matched to run with the mod man intake I bought from them too. I have since changed the direction I was going with the 472,and ordered the 705 horsepower top end kit from Edelbrock, so the whole top end from the 472 Hemi engine, and the new parts from Indy Cylinder Head and going into the 426 Hemi engine I am building.