This form is being used to collect Engine Unit Numbers or Engine Serial Numbers of Pontiac blocks. This is the 6 or 7 digit numbers above the Engine Code letters. (1969 and after, starts with a 0 usually). I am trying to correlate this data with the VIN of the car it was in originally. If you don't want to expose your VIN you can use x's for the last 2 or 3 digits of the VIN. You can also use the VIN that's stamped on the 69 and newer blocks. I.E. 20R115xxx If you would please, try to also input the block date code. Thanks
In earlier years, Pontiac spoke of Motor Unit Number (MUN),or Engine Serial Number, later they identified it as the Engine Unit Number, hence EUN.
It is the sequentially assigned no. stamped on the block at the Engine Assembly Plant in addition to the Manifest Code (engine code) which defined the application and componentry that had gone in and on the Engine Assembly. The Manifest Code could later be selected at Final Assembly for a particular build calling for that Manifest Code.
The MUN or EUN was stamped regardless of engine type from a single number set.
The EUN started with 6 digits at 000001 (early in the '69 Model Year they went to a 7 digit no.) and every year they restarted the count.
In '69, the Engine Assembly Plant had to continue assembling '69 Firebird motors well after they began assembling '70 motors. So they were stamping 08xxxxx '69 EUNs at the same time they were stamping 0000xxx '70 EUNs. But normally, prior Model Year Engine Assembly production would have ended before new Model Year production began., save for perhaps some "pilot" type production.
Sometime around 1973 the leading zero became chipped and looked like a 'C' or '(', which should be recorded as zero.