That information is incorrect. (By the way, that site is riddled with incorrect information.) The correct information is
HERE, and was taken from Chevrolet Bulletin 66-164 dated December 16th, 1966. In it (Page 2), regarding the L35 (396/325) engine, it states "We currently anticipate production will start during the latter part of January."
The pre-production engineering development and testing for the big block was done in November and December of 1966, but the actual release date of the L35 engine wasn't until late December, 1966. That's when dealers could start ordering them. The very first L35 cars rolled off the assembly lines in early January, 1967. I no longer have access to the database, but if I remember correctly, the first L35 car we have in the database is the second week of January, 1967. Kurt, Daniel or Bryon will have to verify this for me.
The engine you have is a restamp. It doesn't have the correct fonts, is the wrong size and the original broach marks are no longer there indicating the block's been decked.
If you didn't pay a lot for the car, enjoy it for what it is, a big block clone. However, if you paid a lot of money for the car and it was represented as "numbers matching", get your money back. If you need verification from a professional, contact Jerry MacNeish at
CAMARO HIGH-PERFORMANCE. (Jerry's
THE authority on the first generation Camaro), and he can inspect the car for you. If you end up needing a lawyer, contact Bryan Shook at
VINTAGE CAR LAW. He specializes in these types of cases.
Ed