Crank pulleys will not bolt to balancer

What front end engine set-up are you using?

Are you using the 65 timing chain cover and cast iron water pump?

Or with the 74 318 timing chain cover and aluminum water pump?

Run the balancer for the 318, but if you are using the 65 273 timing cover, just remark the TDC mark as it's different from 65 to 74...

Are you using the original radiator from the 65 car? Then the 65 timing cover should be used with the cast iron water pump so the radiator hoses will be in the correct locations.