Tony- I would suggest emailing Chris for dimensions. I believe he told me they would clear conventional roller rocker valvetrains; but if you have something exotic like stud girdles, etc. it might be tough. I think somebody makes a spacer for those applications but that might just be one more place for an
oil leak. I have seen some pretty neat "sheetmetal" valve covers and there are sources that can "etch" anything, any color, on them. I bought a set of low end Moroso covers for my 427FE and had a custom plate etched in three colors with a Ford logo and 427 script and bonded it over the Moroso name. I got a lot of compliments for very few $$$.
REgards-Dandy Don