seats
 

will 64 seat covers fit 69 seats without the headrest

No I don't think so. They wouldn't be the correct pattern either.

Not sure put I think 69 thru 72, maybe 68 as well, are the same seat. Earlier Chevelles were a a different seat.

68-72 are basically the same...as mentioned, earlier seats are different.
Suggest sells the '64 covers and buying the correct ones. Or, are you trying to install '69 seats into a '64 and want to match the pattern?

thanks for the responses,yes i'am wahting to put 64 covers on 69 seats,it is a bench seat,it was a bolt in it looks the same as the orginal except for headsest.