The hose is between 1/4-3/8" ID. It's probably pretty close to 5/16", actually. Depending on the size of the fittings on your pump, you'll probably need 5/16" for one end and 3/8" for the other. I believe the inlet on my pump was larger than the outlet for some reason. Just go down to the auto parts store and see what diameter fuel line will work. For splicing, you can use 1/4" or 5/16" barbed splicers and hose clamps to connect your fuel lines. You might be able to find those at the auto parts store as well, but you can get them from Home Depot. A 90 degree fitting isn't absolutely necessary on the pump, you can just run a longer section of fuel line to compensate.