I have a theory that I want to validate or disprove. I'm wondering if the Ram Air Inlet option was actually shipping from Pontiac on early 1969 Firebirds equipped with the L-74 engine.
I have not seen an invoice from PHS that shows the RAIII (or HO) engine (code 348) along with Ram Air Inlet option (code 611) early in the 1969 production run. Does anyone have an invoice they can post that is prior to March 1969 ... or even one as early as Fall 1968?
Also, I'm interested in determining when Pontiac changed the nomenclature for the same L-74 engine, from "FB 400 R/A" to FB 400 HO" on the invoice and window sticker. I've seen the R/A designation through December 1968 and the HO designation in March 1969, so somewhere in between was the switch, just trying to narrow it down a bit more. Thanks!
There was some heated discussion previously on the RA vs HO designation in this thread below:
