I installed a new ZZ383 crate motor in my 40 Willys coupe and have only put on about 100 miles and its started knocking. Not a loud knock, just barely noticable. I've traced the knock to the passenger side either the #6 or#8 cylinder. With a mechanics stethoscope touching the block you can actually feel the tapping. It appears to be at the top of the block at the head. The tapping disappears as you travel down to the oil pan rail. This was not there in the beginning. I broke the engine in as per GM's instructions but I only went to 4000 - 45000 rom instead of the 5000 rpm spec'd by GM. I read somewhere (not sure if it was on this forum) of a similar complaint and the problems/difficulties trying to deal with GM and the warranty. I don't know the outcome of that issue. Can anyopne advise me, first is this tapping going the be a concern and second was that person successful with his warranty ?