The smaller flywheel has 153 teeth and uses the "straight across" bolt pattern starter. This is pretty much constant for I6 (194, 230, 250 and 292) and smallblock "twin-four" motors.
This has been a handy thing to know, specially since I had to juggle flywheels, clutches, bellhousings and starters in my 63 Nova before I got a combination that would work. (The Chevy II bellhousing is a strange beast all unto itself.)
I'm not positive about the I6 motors, but not all V8s are drilled and tapped to accept both bolt patterns of starters. In this case, some of the hi-torque mini-starters will work. I haven't found any pattern to why some are drilled and some not.
