You can get the year of manufacture of the vehicle it came from, by reading the first two characters of the engine number
Mine is GA 11nnn which corresponds to the last 7 characters of the VIN of the donor car
In my case GA refers to November 1986
The number you quote isn't the engine number. I believe YBB relates to the engine type, in this case it would have been fitted to 3 door and early Sapphires (but I will stand corrected on that if wrong)
the actual engine number will be at the side of the engine down near the bottom of the block
Check your year code here - http://www.burtonpower.com/tuning-gu...ure-dates.html