best place to order 1970 dart slant 6 gas tank and fuel sending unit

Wherever you can find that sells Spectra products. They are made in North America in Canada and are high quality. They are usually all over Ebay......but with something that large, I would want to buy from a local retailer. O'Reilly usually has a Spectra option in their catalog. You can find them cheaper, but sometimes buying locally is better for warranty issues.