My point exactly. Pontiac defined, on the Master Order sheet, the 348 as "L74 400 HO 4BBL V8 - Engine option for Firebird 400 Order in place of 345" and gave it an RPO of 348. T42, RPO 611, says "Hood Ram Air Inlet - Optional 348 Only"

The Master Order is what was used to order a car from the factory and was used to generate the Broadcast Copies when entered in the system. The Dealer Invoice was a separate process run by accounting.

So how you then take the exact wording used by Pontiac in 1968 and 1969 to order a Firebird and alter it to fit your own definition flies in the face of fact.