Well, if you go to hot heads they sell some that say you need to machine you heads and they don't look like those from Mancini's website.

PAW, which only sells Hemi stuff on eBay now....his stuff looks similar to what Mancini sells, but doesn't require machine work. If you get in contact with him threw eBay he will usually put it up, anyways that's what he has done for me.

But..........I've wondered the same thing as far as the 426 stuff working on the the early Hemi stuff? My PAW covers take stock 426 spark plug tubes..........so would they work?