The oil ports on a gen 5 or 6 go directly to the galleys at full size TIMINATOR
Since you obviously directed this to me I'll respond only to this. Then I'm out because I am not interested and don't have the time for cat and mouse games.
The problem is, AGAIN, using these ports for external filters and coolers is that the ports (threads) are too small to run an adequate line size for any high performance engine. I wouldn't use them for even a stock rebuild in a boat. GM uses steel hardlines that have a larger ID than hose, so they work for stock, street driven vehicles.