318 crankshaft specs

If the engine was never balanced then i would do so, and give them the new harmonic balancer and flex plate your running on the motor so they can make it right.
You have gone this far and this is such an important part of a performance engine.
Telling the shop all the information about the engines parts will help them, and it's good to know what was installed in your engine.
After they balance it,you will know how far off it was also.
The holes are drilled on factory cranks.
This does not mean that your engine was balanced when rebuilt.