Where’d you get the seals for the hoses?

I plan on replacing the radiator soon. I plan on sticking with the older style radiator with more hoses I believe. Rather not replaces hoses if I don’t have to.

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e70 - purchased 6/2018
e36 - wouldn't pass smog at 190k 2016
e53 - transmission blew at 225k 2012
e30 - sold as it was a little slow for a DD and burning oil at 220k 2011