Opening Cast Aluminum Valve Covers for PVC Grommet

I had the very same question on the set that I got for my 383. I was worried about the whole hammer issue too but I called them and asked them about it. They said that it was prescored and would not take much effort at all to get the hole cleared. so I took a big punch and reluctantly tapped on the end of it and it just popped out. I did have to enlarge the hole too to get the grommet to set in there correctly though.