Are you really trying to argue? I am the one who blazed this trail. You cannot move the engine further back into the engine bay of a Z31, than what I did. I have 1/2" between the head and the firewall, using the factory (fore aft) locations. If you put a vertical radiator in like I did, you will have airflow problems along with overheating issues. Your best bet for radiators is wait until tomorrow, when I pick up the first batch of aftermarket direct fit rads for the z31.
You might want to look at my build thread again.
Rb Z-31 - HybridZ