Went to a large fastener outlet and got two M16x1.5 jam nuts for a $1, couldn't beat the price. Ebay has them except like a lot of things on the internet the shipping was stupid. Anyway jammed them together and no problem spun the nipple right off. I've been looking for a source for the fuel heater upper O ring and again prices and shipping get stupid very quickly. I went to the Dodge dealer and found them for like $6 each. It's a 29 cent O ring!!! But that the best it gets since they don't add on $12 for shipping. Bought two and when they came in to my delight they are the real deal and not the square fuel filter one. Haven't installed one yet, but fully expect it to seal nicely.