[Mr70]

....The current thinking is the embossed bottom PF-25 was used through remaining 1969 production with the (un)embossed PF-25 used at some point thereafter.

Thank You for sharing this research.
Has it been determined when exactly the <u>(un)embossed</u> white PF-25 came into effect?..month?..year?


My current challenge is to determine when in the 1969 model year that change from the PF-29 to the PF-25 occurred.....I know that by October 1, 1969, the PF-25 was specified as the SERVICE oil filter for all 68-69 Corvettes, so it had to have happened sometime between October 1, 1968 and October 1, 1969, even though the PF-25 did not officially, formally, and finally replace the PF-29 for SERVICE until January, 1970.

Just to add,I see the white PF-25 #6438261 filter specified as being in effect for the 1969 Corvette as late as March 1st,1969.