On the 265, here is the story.
I am sending it to the Tri Five Nationals Aug 14-15 in Bowling Green. They have over 1200 cars registered already. I actually acquired it from a mutual friend of ours, Lamar Walden along with some other stuff. Lamar got it back in the 1980's from the man himself, Zora Arkus Duntov. It had been the test engine Zora had built to stuff into the Corvette. If you remember they built the 162hp 2 barrel, the 180hp 4 barrel and then later they built the 195hp 4 barrel solid lifter engine. This test engine Zora had built is the 195hp and is the first production engine built. Some of you might know about Zoras passion for making sure the engine already in the production works was strong enough to beat Ford. I have a 3 page letter Zora wrote to his boss about how important it is for Chevrolet to get in the game because Ford is walking away with all performance sales.
On the engine, Zora shared that they ran this engine in a black 1953 Chevy 4 door and did so until something broke. Sure enough it did, a rod broke and did some pretty good damage including breaking out the bottom of 2 cylinders as well as other stuff. Zora kept it around for years as a training engine since it was not going into a vehicle and was a test engine.
The casting date is in fact August 12, 1954 for both the block and the 4 barrel intake manifold. I also have a pair of heads with no casting date at all on them.
If you were to read Zoras letter and see some of the early photos of the wooden mock up engines you can see from the date of his letter in Dec 1953 only 7-8 months later he has had the first production small block engine built as the performance engine he wanted to have. The very first cast 265 2 barrel that came out is in fact in the Chevy museum. Doug Marion did an article on it, however, this 265 is the first production engine they built.
In Bowling Green this 265 will be displayed with a sign, Where It All Began and beside it Chevy will have there new LT small block with a sign, Over 110,000,000 later.
Is will be the first time this engine will have ever be displayed in public.
Hope this helps fill in the blanks a little bit. Pat