Actually, I have...not on a Chevrolet. Considered the 'best' Cross-Ram for a small block Ford was the Shelby 289-302 version. It came with a single or dual carb'ed top plate. With the single Holley, it was a real screamer, and street friendly. I'm sure the Chevy version can be (or is just as good) for what you're intending to do. That said, hopefully more qualified Chevy Cross-Ram guys can chime in.