Replacing the tiny, crappy electric pump with the stock mechanical Carter, adding the short steel fuel line from the pump to the vapor separator the previous owner threw out, and new rubber hoses, of course. Go to measure to make sure, and I have a 3/8" sender with 5/16" line from tank to pump. Not a '68, but a September, 1969 built '69 R/T. Why would they use a 3/8" sender and only a 5/16" line the rest of the way? Do I use 3/8" or 5/16" line at the sender to connect the two different size lines? I'll use the $.95/foot stuff and grater clamps to see if everything works before buying the $20/foot KV hoses.