Re: V8 spark plug fitment?

Posted by Dave Brownell On 2016/8/15 8:20:00

Cast Dome is a new term for me, perhaps either a way to save some machining costs in a tough financial crisis, or just a better way to shape a more efficient combustion process. I'll add this to my list of changes made to these cars between 1955 and later 1956s. Not having access to the cited Service Counselor bulletin, is there a reason or benefit given, and what mention is made for the spark plugs being changed?

Just like the early and late 1963 Corvettes being distinctly different parts animals, was there a watershed production change when 1956 cars turned into something else? Or did running changes comprise most of the differences between early and late?