1. I have 68 J code 302, all numbers match,except heads have 2D15, 2D29, does this mean they are from a 72? and think they already have hardend seats in it?
  2. i believe that is the casting date, it should start as C6 for 1966 ,C9 for 1969 and D0 for 1970 so 1972 would be D2 at the start of the numbers . the number your are looking for is under the head on one of the intake runners a pair of 66 heads i have say C6OE .
  3. if i remember right the 2 is the month Feb. ,D is 4th shift and 15 is the day of the month so it is February ,4th shift ,15th day =2D15. as i said the year will be on the bottom of the head.