I bought a Lockhart oil cooler kit that came with a plate that went behind the oil filter and included fittings and hoses that screwed into that adapter plate and went to the cooler. All very easy.
There were many kits back then to fit most popular air cooled bikes. Two popular brands were from Lochhart and from Derale. Don't see those around anymore. My son got a Derale kit for his GS1100E and drilled and tapped holes in the oil filter cover per instructions, I forget the details.
That plate for my CB750 Lockhart cooler had a cavity that picked up the pump flow where it came out of the block and directed it out one side to the cooler and the return flow came back in the other side and forard into the oil filter cover so it was a full flow cooler as I recall. Cooler needed to be covered in real cold weather.
