273 Pistons

1969.I think the book shows up to 67 only because that was the last year for the HP version, which was 10.5 or so compression. the two barrel was 9.0 I believe

I presently own a 1969 with the 273, and rebuilt it in 2012. I needed to go .030 over, as the original pistons were.020 over and I had to clean up the bore. By a miracle, I found a set of .030 pistons new in the box at an old parts shop in Puerto Rico! They were on Ebay, and had been on their shelf since 1970!
in addition, once we got past the language barrier, I asked them if they had any more old mopar pistons. They said;SI, 1968 340 10:5 and '030 over, and 1971 9:5 .030 over!. I bought all their sets on the spot.They thought I was a crazy Gringo.