I just spoke with the manufacturer on the phone. They will exchange my kit for a mini-ballast version that will fit in the nose. He told me the light runs at 480v (even higher at ignition)... i.e. not something I want running across the bottom of my gas tank.

I'm going to first see if the bulb will work again without the wire extension as Ceil suggested. If so, I'll see if there's any way to mount the 4x4x2" ballast in the nose.