I was doing my timing chain. Found the key in the crank keyway is round? To my knowledge engine has never been apart. Still has original gm nylon gears. Is a round key the factory key? Should I replace it? Its a 2 barrel car, it does not have a harmonic balancer. It uses a pulley.

1964 crank hub

 

I'm waiting for others but that DOES NOT look correct.
Good luck!!!

 

Agree that it doesn’t look like the typical key but if there’s no movement then it’s doing its job correctly.

 

I do not think that is correct even for a 67 two barrel motor. All 67 two barrel motors did not have a balancer but had a hub that was counterweighted and the pulleys bolted to that, used the typical 1/4 square key.

 

Who knows what happens to these cars in 58 years since leaving the factory. Since you're there swap that round stock out and install a square key.

 

It's been apart. That is NOT a factory installation. Someone lost the original key and stuffed in that piece of round stock. Looks like your timing marks are off by about 5 degrees as a result.

 

Agree it causes the balancer to be out of position in relationship to the crank so ignition timing marks will not be accurate.

 

Its a pulley and hub, this car has no true harmonic balancer since its a 2 barrel engine. I will replace with square key. It still has the original timing gear stamped "GM". Looks like only 1 or 2 nylon teeth broke. Its a lower mileage car. Thanks for the advice....

 

Ok it causes the hub to be out of position in relation to the crank... ignition timing references are still incorrect.

 

I reminded of the old square peg in round hole adage. In this case a round peg in a square hole. Since you are already doing the timing chain this is an easy fix and should be corrected.