I have heard that the Pinto / YB like to have their coolers mounted upside down. It was explained that it works better with the natural pulses from the oil pump.

Now, this came from a very experienced YB engine builder on another forum. I don't want to sound like the obligatory pub talker putting in his 2p worth - was a genuine comment at the time from the guy.

Maybe someone can confirm / deny this?

Just spotted Rich has done it lol