You can break in the cam on a stand, but the rings need to be loaded for break-in, so it's not even practical with the engine in the car and in gear unless you can drive it.
Since as stand won't see WOT or even sustained load, the radiator can be pretty small if there's a shrouded fan, either to get only air from the rad (like stock), or as a pusher only air from outside (big hose to somewhere else in the shop or outside so the rad doesn't just re-circ hot air.
