The COPO 9511 code was used in 1969 to specify either a 4.56 axle ratio (via 9511DT) or a 4.88 axle ratio (via 9511CB). Without utilizing this code, the highest numerical RPO axle ratio available in 1969 was 4.10, unlike the '67 and '68 cars which anyone could order with a 4.56 or 4.88 ratio as an RPO. I would think there were fewer 4.56/4.88 builds in '69 (vs. '67 or '68) due to those ratios no longer being an RPO -- just my guess.
Has any new information surfaced in the past decade or so that sheds light on the number or percentage of 1969 cars in the general population of all Camaros, or just the Z28's, SS's or COPO 427's, that were ordered under COPO 9511?
There have been a couple of postings in 2024 about COPO 9511 on the Yenko website, but with no new information on how many 1969 Camaros were built with 4.56 & 4.88 axles:
https://www.yenko.net/forum/showthread.php?t=114303&page=6
There are no production records for COPO items, since they weren't included in the option totals. The COPO totals we do know came from personal records (9560), deduction (9561), or dealer info (Gibb Novas).