The Victor heads have really short valves which cause a bunch of problems in terms of spring height and room for the rocker arms.

You most likely need to work backwards from the valve lift that you're trying to hit. Once you know that you need to figure out how much room you have for a valve spring and then go spring shopping. A beehive spring would be perfect if you can find one that will work with your camshaft. If you can't find a beehive that fits then look at the small diameter "special" springs from PAC and others.