Having a run stand or putting an engie in a car and running it is a bad idea, only if you keep running it with out a load. I have a 294 engine on a stand right now. It has less than a minute run time. This proved that there was oil pressure and the timing was clos enough for start. Tomorrow a different ignition system will be installed to add a machanical advance. Engine will be restarted to prove these items, run time less than a minute. Thursday the 3 new carbs will arrive and the new center carb will be installed along with radiator and water. Engine will be started and run at hi idle 1500/2000 until water temp reaches 190/200. after cool down the heads will be re-torqued and the engine shipped to the dyno where it will run a series of loading runs to seat the rings. After that, we go for power. I say all thei BS because running a new engine can glaze the cylinder walls and rings preventing them from deating properly.