[kob153]

112517yb is stamped on front right top of timing chain 26n522430 is stamped right next to timing cover for some reason i cant post pics on here i tookpics of it

[johnta1]

The 112517 is the Engine Unit Number (or Motor Unit Number)
The YB is the engine code (needed for my search page)
The 26n522430 makes it a 1976 Pontiac Firebird.
(the 522430 is the last 6 digits of the VIN of the Firebird the engine came from)

That makes the date code J205, which was probably mis-read as I said.

So the block was cast on Oct 20, 1975 for the 1976 Model year.

Still a 350 unfortunately.



With that partial VIN (26n522430) you could send it to PHS and find out what the car was originally optioned with. (for a fee though)