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:
Hmmm, whilst sitting on the pot perusing an old Competition Products catalog (no I do not use catalog pages for wiping), I noticed that ALL of the spread port/low valve angle heads (Brodix "Big Duke", Dart "Big Chief", Pro-Filer "Hitman" etc.) have 4 bolts top and bottom.
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod
1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod