Are all 360's balanced the same?

A 360 Magnum motor requires a specially balanced flex plate or flywheel.

I believe the one you are looking at (Beginning Year 1971 - Ending Year 1983) is for LA motor, you should be OK if your motor is not a later (Magnum) 360.

BTW - Summit is VERY forgiving if you make a mistake. They are usually my first choice.