Re: 69 ZL1 engine info....Help!
Chevrolet by the Numbers has this, 3946052, 1969 Camaro, Corvette 427/430 4 bolt.
Text is such,
"This special aluminum block was installed in sixty-nine 1969 Camaros, and two Corvettes during the 1969 model year. This was the only factory-installed aluminum block ever installed in a Chevrolet production car. The primary purpose of this engine was to produce an all-out race engine to the general public, with a significant weight reduction as well. This block had steel cylinder wall sleeves and 4-bolt main bearing caps. It was also produced for service applications and was a by-product of Can-Am racing technology. It also featured special provisions for dry-sump oiling. The lifter gallery has specially cast bosses to accept the four extra studs used to anchor the cylinder heads. See Chapter 5 for head details. There are reports that the first ZL-1 blocks had the casting #3946053 but that has yet to be proven".
Take a look at the OP's post, his engine number is 3946052, and, in the text, it mentions a not proven item, another block number 3946053, and, in CbtN, there is NO 3946053 listed. Since CbtN deals with production line numbers only, the second block number may well be a CERV number.
No date code info. However, if I had to speculate on a date code from those 5 numbers, 05317, I'd think the 05 is the month, May, the 31 is the day, 31st, the 7 would be the year, as cast, 1967. I do believe these engines were used in earlier than 1969 Can-Am cars, and other super specialty applications, and it is not beyond thinking they had a few engines that were produced before 1969 for "other stuff", or, in anticipation of producing another vehicle application, or, spare parts production, engines. It is a very remote possibility that this engine wasn't intended for a production Camaro, but was a parts department spare engine that got sold outright. We may never know, but, it may well be a lot more historic than it appears. This might well be the reason for the smaller number 2.
Are there any numbers stamped on a pad at the front of the block on the pass side, just in front of the r/h head????? I can't see clearly if there is a pad at the front of the right hand head deck face or not. CERV block wouldn't have one.