cant answer about the ability to change heads from block to block, but i can give insight to the pan situation. i know on 12v engines, the oil pan is generally higher capacity than what used on the dodge. the pan can be reversed, but it's likely the oil pickup tube will not work, its shorter due to the fact it draws out of the front sump. dodge versions draw from a rear sump, therefore the draw tube is much longer. its possible to use a dodge tube,with a higher capacity pan however. beaware that the bus pan is much deeper at the pan region, and the sump as well. likely it wont give clearence in most pickup apps. give me a week and i can tell you if it will work in a gm truck, my 12v is from a bus application. also beware that early 12v bus engines had a hub on the crank, that will need to be removed so you can bolt on the dodge flywheel.