We got this lower end together. Very nice. It runs a close set of flywheels. We notice everything is real tight in some of these older engines. The flywheels are close to the cases, the scraper . . . the rods can be very close to the baffles . . . and a bit different assembly than overhead valve motors . . . they omit a thrust washer, etc . . .
Before doing one yourself - Read the manualfor Big Twin Side Valve