The valve covers I am using are stock(replacements) but are not tall. I cleared the poly locks for the HR cam by cutting them down about 0.100" on a lathe. Turns out the top part of the rocker itself touches the valve cover so I am using two gaskets. Spacers are available also if you want to use stock covers with roller rockers. Hope that helps answer your question.

Nice build still going on mine was wondering what valve covers you are using I can't seem to find a tall pair with the fact look I hate the ones I have on it now went to the show this weekend nothing if I had a name I might be able to locate them anyway looks great mine been down 5 years got plates for it last week frame off resto all the goodies..