Gentlemen, What is the difference between the early nailhead manual flywheel and the one that fits the later nailheads like the 401 / 425? I have heard the bolt pattern is the same but the center hole is larger on the early flywheels. If this is true can you make a spacer ring and use the older flywheel? Ron
Ron, there is currently a similar discussion on the Yahoo nailhead board. If it is a flywheel from a 364, the balancing differs from a 401/425. There is also a difference in the location of the ring gear... The '63 and earlier flywheels have the ring gear 3/8" to 1/2" further from the block, so the starter is different. Poston offers new flywheels for 65-66 applications. You may want to consider that route.
