There are three hose diameters. Usually it's 15/16" Vapor, 3/8" Feed, and 1/4" Return. Take em off and take a sample with you to the parts store. Get SAE J30R9 hose. Gates, Goodyear, Continental, etc all make SAE J30R9 compliant hose... and don't use worm clamps... you'll regret it. Look back a few posts for my writeup.
Replace the PCV and Vapor Cannister purge and vapor hoses while you're at it. Use SAE J30R9 for the 5/16" vapor line and I believe 3/8" for the half melted or rock hard purge and PCV hoses to the manifold or carburetor base plate. You can get away with J30R7 for the PCV and purge hose but you're already buying 3/8" J30R9 so just get a few more feet...
BTW the original hoses will be J30R7. It's been deprecated from liquid fuel usage by the SAE since it doesn't provide as good a vapor barrier and isn't as resistant to alcohol based fuels... even using the newer rubber formulations. The 5/16" vapor line could occasionally see actual liquid fuel so don't use the J30R7 hose there.
