400 rwhp will definitely take some headwork, but you don't need a huge cam. The most important thing when building a car is to use parts that work together. For the engine, this usually means getting a H/C package from one vendor. That's the best and easiest way to make sure the two most important components of the engine will work together. However, this isn't always the cheapest way.

They should also be able to recommend all the supporting mods you will need to make that package work well. I'd suggest looking at getting a set of the new Dart heads ported and a matching custom cam. Advanced Inductions has had some good results with them and I bet Lloyd Elliot can work with them as well.

My question to you is: why 400rwhp? Just for bragging rights? Maybe you should try other mods that will make you faster without boosting the power first and see if that gets you where you want to be.