The very early Cooper "S" models had a small 10 row oil cooler mounted at a forward angle under the radiator. If you still have an original- then you absolutely need one of these. Remember that in addition to their obvious purpose, oil coolers also act as a debris trap. Whenever a motor has lost its bearing or anything of question, you should replace the filter. On a race motor your should replace the filter every time you rebuild the motor!
This unit has -10AN fittings vs. the standard hose clamp hose fittings on the MOC10ROW.