I have my sandwich adapter fro my oil cooler, but I have a question. Which end faces the engine, and which end faces the oil filter? Or does it not matter?

Its the EMPI one. One end has a spring over the return hole, the other end does not.

Also, which end is the output (to the thermostat) and which end is the input (to the engine). The blister pack came with no directions.

Zach

Zach, as far as in and out go....are there no flow arrows on the base or on the supply connections?

Not that I can see.

Wierd

mine was marked... IIRC there was one side with a little ball valve that was engine side, and the other side was oil filter side... then the outlets for the NPT fittings was marked with hard to see arrows.

One side should have an O-Ring or rubber gasket. That's the engine side...

Oil goes into the filter around the perimeter, and oil exits the filter out the center hole. So the threaded fitting that opens towards the motor is the out-to-cooler and the threaded fitting that opens to the filter is the return-from-cooler.

The sandwich adapter should have a large o-ring or rubber seal. That goes against the engine filter console.

Is this the one?

Mark, that is the one.
But it did not come with the large seal, just the groove for one.

Zach