Ok, what was the conclusion here. I have the same question...360 into '67 Dart 'vert w/273 now. I assume I have to use the weird 360 damper as it is a cast crank, correct? Do I have to use an early timing cover as well? I plan to use an early 273 water pump and would like to use the 273 brackets and pulleys to retain the 273 "look".