Well, after searching the web for a special tool to put the piston pin rings back onto the pins, and not having much luck, I set that project aside and started searching my mom's place for more parts. After rooting around one box, I found a brand new item in a bag. For several seconds I coudn't figure out what it was, then the light bulb went on. It was the piston pin installation gauge for the clips. My dad had already ordered it years ago in anticipation of putting the engine back together. I raced home and after a few botched attempts, both pistons were on and done. I lowered the tubes (cylinders) and slapped on the heads. I attached the new intake manifold and the new Mikuni carb and air filter. The engine is done until I get it back on the frame. She's looking good!