I just went and grabbed my 1978 mopar book to read up on the crossover.
It’s total nonsense. If the pressure stays the same with the crossover then oil speed is the same and it is NOT an oil speed issue. Read through it. Everything they do is to get oil from the lifters to the mains. If you are running solid lifters, why would you want ANY oil at the drivers side oil gallery. You wouldn’t.
That whole part of the book is nonsense.
You show me from an hydraulics engineering book that you can change oil speed at the same pressure. I’d love to read it.
In the end you can’t block off oil to the drivers side bank and then put it back and tell me you fixed anything.
Edit: I forgot to mention that if you run hydraulic lifters you have to put oil back to the drivers side. There are better ways to do it than a crossover tube.
Same goes for pushrod oiling. If you are going to oil through the pushrods then you have to put oil back there. There are better ways to do that than a crossover.
The crossover is the answer to nothing.