Brian, between the two of us I hope we get one good clutch to get us to Nelson! I'm thinking Kathy will end up towing us most of the way. I spoke with Rivera's so-called tech rep and I think I would have been better off talking to a brick wall. The more questions I asked the more vague he got, anyway, really surprising for a company that appears to produce a high quality product. Even if they can't tell you the exact measurement, they should tell you how to determine the exact measurement in the instructions. I think Chris has it right, at least there is logic in his thinking, but Rivera's input was pure anal extraction. We'll see tomorrow.