[tubman]

"Shoebox", didn't you have a pair of Edmunds heads that needed some work? If you still have them, are they both unusable, or just one? In my never ending quest to find usable Edmunds heads, I have accumulated a couple of odd extras. I just bought a set with a good left (US driver) side and a cracked right head. If you still have them, perhaps we should discuss what we have and maybe we can come up with a solution to your problems. Best case, you come up with a good set of heads; worst case, I might buy yours to add to my pile of culls. I think it might be worth looking into, as I am convinced of the superiority of the design of the Edmunds units.

And "69a", that is troubling to hear about the Navarro heads. If true, it brings the quality of the entire design in question. I have never paid much attention to the idea that the Navarro's are "one of the best flowing heads" since with flatheads all of the ports and valves are in the block. In my book, getting the most compression without hurting the flow too much is is the main concern. This has more to do with quench and flame front travel than any esoteric contouring of the head surface. I would suggest trying to unshroud the plugs by using the longest plugs possible and some minor contouring of the heads around the plug. One other thing I might suggest is using the proper length "surface gap" plug. These are usually found in 2 cycle outboard motors. I had a 276 Merc with Offenhauser heads years ago that I couldn't get the proper reach plugs for. I ended up using surface gap plugs out of a 65 HP Johnson "Loop-Charged" triple that worked very well. That engine had a complete MSD ignition system, so I had enough oomph to fire the plugs. The only problem I had was that the spark was so hot that in a year's time, it burned through the coil wire tower, ruining the cap. Other than replacing the cap once a year, it turned out to be a great setup.