i go to the "help" section at your local parts emporium, and get one of those expandable/flexible, "heat stove" tube things that go between the air cleaner intake tube and exhaust manifold, these were used on almost every mid70-80's vehicles, and come in several sizes, including 1 1/2" and 1 3/4" which is your standard upper and lower radiator hose sizes. i then just form it to the shape i like for the hose routing needed, then hit the parts store hose selection until i find one that will work for my combination. sometimes, it is necessary to employ straight sections of hose and bend tubing to get the results i am after, but the flexy exhaust tube stuff works great, holds it's shape until you are done, and then you just collapse it back to the straight, as packaged shape and use it again on your next project. hope this may be of some help.