What I mentioned is true.The Jasper rep I know brought in a 3100 cam that was broke in half and he explained this clearly.GM does not do this.The 3.4 is known for eating cams up and washes out the cam bearings.I scraped one 3.4yesterday and the cam was bad with washed out cam bearings with about 150,000 miles on it.It was in a Chevy Venture van.