I have a Holley spread bore list number 8210-1 and I do not know what size it is. I am thinking 850. Before everyone says its a 6210-1 it is not it's 8210-1. It has front and rear metering blocks,air screws on the front block. 50cc pump on the front , standard pump on the rear. No fuel transfer tube, center hung floats. I cannot find anything about it.