Interesting you should ask. Here is an E-mail string I sent to Bill on the same subject. You can see it was somewhat of a dead end. I have taken a few characters out of Bill's e-mail address but it is easily found on a web search.

Back in 2011 it was among our first year I don't recall the judge for that car but it has taken me a few years to get the judges in place that I am very confident with

Bill Braun
MCACN Judging Chairman
Tri-Power Judging Chairman
NCRS Director Region V
Corvette Museum Founding Member 641

On Feb 1, 2017, at 7:28 PM, Tom Cahill wrote:
Thanks for your response. It would have been at the MCACN event in 2011. A blog I was on said Ron Mroz usually judges the full size cars but he was out that year for some reason. I am familiar with the 3904351 427 casting in '67 but not a 3855351.
Tom C.________________________________________
From: Bill
Sent: Wednesday, February 1, 2017 2:27 PM
To: Tom Cahill
Subject: Re: Your name is used to document this car
Tom I personally did not judges cars at show I am the judging chairman we usually have 6 to 700 cars there it's hard to remember one car. Let me know what year it was judged and I'll see if I can track down a judge that remembers the car

Sent from my iPhone
Bill Braun
MCCN Judging Chairman
Tri-Power Judging Chairman
Corvette Museum Founding Member 641
In Feb 1, 2017, at 4:20 PM, Tom Cahill wrote:
https://www.mecum.com/lots/SC0517-282484/1967-chevrolet-ss-427/
Hi Bill - I am interested in this car but can't seem to find any reference to the block casting number in any publication. The owner says the casting number is 3855351. They also state you validated the block as correct for a 1967 425 HP 427. Can you tell me where you found this data? Thank you. Tom C.