I slid the pistons into the cylinders, then installed each piston/cylinder assembly onto the crankshaft. The cylinders are held in place by some aluminum angle, which in turn is held in place by some 1/2 inch steel tubing over the case studs and some 3/8-24 nuts. They are necessary because without them, the cylinders would pop out of the case whenever the crankshaft was rotated, and of course the crankshaft has to be rotated to install each piston/cylinder assembly.
Total Time: 9.0 hrs.