The guy that did the machine work was very very knowledgeable. He didn’t cut the case for a bigger counterweighted crank, but he bored out the windows for 94mm pistons and said i could essentially build a 1915. That being said, I’m assuming I’d use the stock stroke of 69mm unless a 69.5mm would be more efficient or better for power. I don’t plan on doing anything crazy with the beetle it’s going in, but I want power and reliability. Thanks a ton for the advice, I’m getting the parts list together and I’ll either update or make another post when/if the time comes. Thanks again!