The Wellman's ARE designed specifically for the CUCV's.I only use distributors I know are reliable and will accept returns and even pay for return shipping of defective products. Ebay is created by the internet and is not real so if you pay for something there is no guarantee. I would feel safer spending my money on lottery tickets and newports. If I am going to spend 100$ it is going to be for the correct parts that were designed specifically for my application.
One of the vendors has an internet storefront. I bought mine through them. Worked great.
Go with the old school 13g's...just hope they don't swell on ya.