BBC open air cleaner base

[red67l78]

Been hanging on walls for years.  It has the right angle tube for the BBC application.  Has flame arestor with 4 small dimples and GM twice around base.  The breather tube has 5 grooves.   2 grooves and small space then 3 grooves.  GM at least 2 times along the length of grooves.  I think base came off a 68 BBC camaro. Any ideas?  Did the rubber valve cover hose change during the different years (67-69)

[william]

Sounds like the base for #6423907. All big-block '68 and SS hood '69s used it; so did '68 Z/28s. It is listed for '69 Z/28s until late October '68 when #6423272 entered production. But I have a later '69 Z/28 Chassis Broadcast Copy and it lists '07' in the air cleaner box.