I purchased a new gas tank and a new sending unit for my 58. Now all of a sudden I cannot for the life of me get a good tight seal with the gas line from the sending unit. No problems with the old unit but this one will be fine for about a week or so then when you open the door that gas smell hits you right in the face. there are no cracks on the flare and no trash inside the pickup unit. I thought about replacing the main fuel line but the replacement lines from most parts stores have an o ring at the end. Looking inside the new sending unit looks like a circular indention for an o ring. Has anyone had this experience with new sending units ?