Jack Russell, The .354 pitch chain was a move by Bob McCulloch and his crew to try to get the chain business. They put that chain on the some of the old 10 series saws so you would have to buy the chain from a Mac dealer and they in the beginning were the only company to make it thus giving them all the replacement business. A .375 pitch or a called 3/8" pitch has a wider gap between the drive teeth than a .354 pitch. They were close but most times when a customer purchased a chain from another saw shop to use on his .354 McCulloch it would end up costing him more money because it would bust the sprocket. The Oregon 68209 sprocket conversion kit became a big seller as people wanted to get a more standardized chain. I don't think anyone has made a new saw with that chain in 30+ years.
