in digging thru my parts, trying to find all the '69 parts to put my 302 back together, I found a couple of seemingly appropriate harmonic dampers, but there are some differences. I have identified the '69 302 damper, since I stamped my initials on it when I rebuilt the engine back in the mid 70's, and had the machine shop add grooves at 30, 90, 180, and 270. It's stamped on the front '7708', which I believe I've read is correct for the '69 Z28.
The other large damper I had, which I believe to be from the '67 302 which I disassembled once upon a time..
It only has a '1' and a '7' on the front (see photo). but I also noticed the keyway vs TDC is not the same as for the '69 damper. Is one of these weights 'slipped'? or is there supposed to be a keyway difference? and if so, why? If so, I assume the crankshaft keyways are also appropriately different? Can someone point me to a document that clarifies this? or perhaps provide clarification here?