I wonder if it,s not the wrong or a defective cyl. If it used the bolt & block method it would be a larger hole & go way back. I havn't been under one of these lately but 51-55.1 uses the same cyl. I've never heard of a balloon flare. These lines were the same for 50 years or more till they started using metric sizes.
Last edited by Wrenchbender Ret.; 04/06/2008 9:36 PM.