327 was made from '62-'68. Doubtful a 327 would show up in a '69 car, unless it was late '68 production. Casting numbers are only surefire way to figure out what engines these are. The codes on the front of the block were recycled on different motors in different years.
The visual clues for a 283 are 4 bolt valvecovers with offset holes, some 283/327s had the oil filler in the intake manifold, points distributor & older style water pump. There may be other visual clues too. Check casting #s on heads, & look for two small symmetrical humps cast into front of heads for the famous 'camel's hump' 327 heads. The 283 Power Pac heads have a little rectangle with a pyramid on top instead of the humps.
