daddio4048
Daddios72
Checking to see if this is the flywheel some say is hard to find?
Came off 72 340 3 speed DusterCan you elaborate on what you mean by a "rare" flywheel? That casting number, 2264598, was used over a wide range of years and applications, and was balanced differently dependent on it's ultimate part number and application. Any idea what it came from? That casting was found on everything from 318s to cast crank BBs. Looking at the balancing holes, my guess would be an internal balance engine- 360s had (3) 15/16 holes drilled closer to the hub, cast crank BBs had a "scallop" flycut into the outer rim of the flywheel, and I don't recall the cast crank 340 balancing scheme but it was a different layout yet again... Without a history or part number my guess would be 318 or '68 through early '72 340, internally balanced. Just my SWAG.
Sometime in the latter part of the '72 model run, they started using externally balanced cast crank 340s which required an external balance flywheel. If you have access to the 340, look at the harmonic balancer. If it's flat with no balance tab, you have a internal balance flywheel. If it has a raised balancing tab on it that says "for 340 external balance only", or something like that, it's an external balance 340 and you have a external balance 340 flywheel, only used for part of '72 and all of '73. As a last resort, see if you can google a pic of a external 340 flywheel to compare balance holes with.Came off 72 340 3 speed Duster