heh, yea I did mean 510. its been a long time. I considered 710 and other half-link but leary of half links and shock loads.
Im very lucky to have McGuire bearings about 5 miles away. They also sell nice industrial chain. However, in the end, my decision is biased toward the anti-drop characteristics of the much taller beveled inner plates and the thicker outer plates. I have an IGH 3-speed jackshaft that is brutal in a high rpm shift and Ive been lucky to have seemingly endless mileage between chain adjustments. We also have potholes from **** here and I used to throw chains just navigating parts of town.