I have some long hose part numbers that I've collected over the years.
Center hose on the front was not available in a longer version of stock, although a Raybestos BH36537 has the right size ends and will bolt directly to the front axle, but the upper mount is straight,not blocked like the original. All it would take is a small bracket to mount it to the upper frame. This hose is about 8" longer than stock. For the rear use a Raybestos BH36537, Wagner F98947 or F88988. As these are direct replacement, and are a good 8inches longer than stock. They will fit 66-77.
Center front hose on 76-77 was also easy. Raybestos BH38235 or Wagner F79350, both were about 5-6 inches longer than stock.