Hello. I have read that a 1 after the VIN's letter means a Firebird left the factory with a V8 engine. I've also read that a 6 after that letter means a Firebird left the factory with an inline six engine. Is this true, in ALL cases. I think somebody told me that some Firebirds that were equipped with 400 c.i.d. engines might have used a 6 after the VIN's letter. I'm not inclined to believe that. Can anybody who knows for CERTAIN clarify the matter?

Thanks very much

1 is the first of the last six digits on ALL V-8 Firebirds.
6 is the first of the last six digits on ALL L-6 Firebirds.

There are no exceptions to this in first gen Firebirds. There are in other makes/models, where production numbers went up over 100,000 and necessarily rolled the first digit.

Thanks very much!