Correct, most of the old Nitro racers had the early 392 type hemi motors a long time ago that had the flywheels fit around the outside of the crankshaft flanges with no provisions for a converter register on the back of them like the new stock wedges and hemi motors made after 1962. They would have crankshafts made for the early type flywheels and clutches instead of buying new ones, some racers are still doing that