I have two #228/#226 COPO ring and pinion sets for sale -
The first COPO Ring and Pinion #3916228 #3916226 set came out of same rear so the wear is aligned unlike mismatched pairs which can be "noisy". Dated April/May of 1969. Set is in very good condition. $1,750 for SYC members.
https://www.ebay.com/itm/223249942819
The second COPO Ring and Pinion #3916228 #3916226 set has the #228 dated May of 1969 while the #226 looks to be a warranty replacement with a date of April 1970. $900 for SYC members.
https://www.ebay.com/itm/223249953698
Thanks for looking and PM with any questions -
Jeff