I would agree if there was a better option than 50 year old heads. Cast iron heads are good for an application like this but it would be even better if there were brand new thick wall castings with quench. That doesn't exist so you have to use 50 year old parts which is a crap shoot. We had an engine on the dyno recently that was a full rebuild using all stock parts (number matching type of engine) and one head let go after a few pulls. That head had been fully rebuilt, pressure checked, magnafluxed, etc. and it still let go after it got a little bit of stress. So the owner had to go find another casting and pay for another head rebuild.
