in early 2003 i made that valley cover for a 6 pak engine i was building. i had always fought the sucking oil thru the intake problem and was looking for a permanent cure. i used it for quite a few years without any issues, but eventually moved away from the idea. i regret not making something with a more universal fit but at the time i was pretty much stuck on 6 paks. i got to where i just addressed the manifold fitment issues directly and left the "band-aid" behind.