Thousands and thousands of buses have 12v pump for an auxiliary heater unit and large heater cores too. 1" core plumbing I believe. These components should be cheap used and reasonable new.I've seen school busses with electric aux. water pump to circulate water to the back heater cores.
If you think a post is SPAM, you can report it using the button on the right top of that post.Spam, again? So soon? I'm on a diet here people!!!