['ol Pinion head]

The dies that were used to stamp the snorkel changed during '69 production. The snorkel used on the '68 GTO-Firebird 400/428HO B series aircleaner (& the '68 Olds 442 aircleaner base) will have a thin long raised line across the snorkel. This detail carried on onto early '69 model 428HO aircleaner bases & on early ' 69 usage Firebird 400 bases, as well as on dual snorkel wide spread '69 GTO aircleaner bases. By mid '69 production this minute detail was gone, with the top of the snorkel being totally flat.

As mentioned above No Dual snorkels bases installed on '69 428HO B series or for that matter '69 Firebird 400's. would have to double ck, but believe the B series & GP's equipped with Instant Air option. the valve and bracketry interfered with pass side snorkel on a '69 GTO dual snorkel base.