I just installed some tall chrome valve covers for future clearance for the 1.6 RR, I was going to put the aluminum valve covers I'm getting for my birthday on but my truck needs them more, December 31st if anyone wants to buy me a roots blower to make the day complete . Anyways when I finished and started up the car I noticed some movement on the side of the PS valve cover. I watched it ??????WTF???? about 1 minute in oil started to puke out. The (stock) rocker wore a hole straight through the valve cover.
Why did this happen??? The valve cover was alligned its not like the bolts were not in the holes, nothing special with the heads just 1972 LT1 heads. This happend to anyone else???

 

Yes.

Sounds like you had them on backwards. (inside-out?) SBC valve covers aren't symmetrical; the side toward the intake should stand up straighter than the side toward the exhaust. If you turn them around backwards, with the inside toward the outside, the slightly more leaned-in exhaust side will not clear the push rod end of the rockers. It will even happen with stock VCs, especially with stock or stock-ratio rockers, since higher ratio rockers have that end of the rocker shortened.

 

Thats what I first though but these were on my truck and have the good old "New GM Goodwrench" stickers on them so it would be real hard to put them on backwards, they are the same diameter both ways and were taken off and installed one at a time, thats whats go me Nothing abnormal that I can tell with the rockers either. i guess I'm going to have to measure them to see.