The conversation is entertaining but the train has jumped it's tracks. Going back to the beginning.
Oldtruckspapa's truck is getting a head job. Pretend you are a mechanic in a shop and you have other jobs waiting. The boss is frowning because you have been too busy flapping your gums. What needs to be done, to get the truck engine ready, before the head comes back from the machine shop?
William of Ockham. “The simplest solution is almost always the best.”
