Well ya learn sumthin' new every day ... I was watching the Gatornationals on TV and saw the Jason Line Summit Racing Pro Stock motor, which HAS to be a BBC, and I noticed that the valve covers had 4 bolts on the bottom (naturally) and ... 4 bolts on the top! World Taekwondo Foundation?! Of course I checked my very own BBC, and ... yah, 3 bolts on top. So, World ... well, you know.
So it took me a little while, Google search not always being so ".00001 seconds 97 quadrillion results (snotty young 'uns that they are)" but finally I discovered that, whilst improving the BBC cylinder heads to 12 degree spread port design, they also added another valve cover bolt:
Whoulda thunk, eh?
1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
1964 Acadian Beaumont SD convert, 283 - factory 195 hp, Powerglide, 3.08 10-bolt - Cruiser
2012 US-built crew cab truck - Daily Driver and Boat Trailering
THEY ARE PRETTY
Yah! That's it! ... but wait, there are 4 on top and 4 on bottom and 2 heads ... it's for a 16 door! Dave