[jhv48]

I second the lifter problem. My Roush, at 13,000 miles when I rebuilt it, had a couple of marginal lifters. Replaced all of them. After the rebuild, I experienced a slight tapping noise. Come to find out, two of the brand new crower roller lifters were defective. Replaced them all again and so far all is good. If it is the lifter, you want to catch it early before it destroys the bore.