[sllib]

Your flywheel and harmonic damper will have to match your engine balance. Take both to the machinist when you build the engine. I have a 427W stroker in a Dart block and decided to make it internally balanced, so I had to buy a neutral balancer and neutral flywheel. The damper was no problem but Centerforce didn't make a neutral flywheel for the clutch I wanted, so I had to go with McLeod, which is much more expensive. I called direct to both companies for this information. If your motor is not a monster go with external balancing to save the money and problems. Good luck.
Bill Stradtner