I remember learning the Aurora engines were modified marine engines, chosen for their low-end torque. Certain critical parts are different than the automotive version - among them the number of teeth on the flywheel gear, and possibly the gear pitch of the distributor drive gear and matching worm gear on the cam. My original engine was replaced with a later 302 block, a 1990 Lincoln, to allow for roller lifters and cam. My builder asked if I wanted to keep the original fuel pump, carb, distributor, etc., and I said "sure, why not?"
I'd love to know if mis-matched gears could be the cause of the remarkable wear (see photo), which gradually retarding the timing beyond it's adjustable range. Once the gear was replaced with the common Ford automotive gear, the engine runs better than ever.