Checked all the local part stores for back E-brake cables for my 68 dually. As a last resort, I tried a local Chevy dealer. They didn't have any but the guy kept looking on their parts locater. Found a set about 80 mi. away at another dealer. Was going to get them sent to me. Then the parts guy said he would check with a company that apparently has a contract with GM to buy up discontinued items. Well a day later I have cables from Vintage Part LLC in Beaver Dam, WI. Price wasn't bad, originally quoted $30/side but the guy Sold them to me for $48.00 for the pair

The ends look correct, but will find out for sure on my next day off.