ON THE BACK OF THE DRIVERS SIDE BLOCK THERE IS JUST THE TREADS WERE ONE GOES I ASSUMING NO ADAPTER BUT ON THE PASS SIDE OF BLOCK THERE IS SOME SORT OF FITTING SCREWED INTO THAT PORT HOLE...ARE YOU SAYING YOU HAVE TO PUT TO OF THE SAME OR 2 DIFFERENT TYPES OF OIL UNITS IN REAR I AM JUST CONFUSED ON IT ...LIKE I SAID I WENT TO GET ONE AT O'REILLY'S BUT WHEN I TRIED TO INSTALL IT ON THE DRIVERS SIDE PORT THE THREADS ON THE OIL UNIT WAS A LITTLE TO BIG...I READ SOMEWHERE EARLIER THAT THERE ARE 2 DIFFERENT SIZES OF THE SE UNITS BUT I DONT KNOW THAT FOR SURE... THE TEMP UNIT IS ANOTHER PROBLEM I DID SAME THING THERE AND IT WAS WAY TO SMALL I ONLY SEE ON THE WATER PUMP HOUSING WHERE THE WATER NECK AND THE HEATER HOSE NIPPLES ARE LOCATED IS NEXT TO WHERE THE TEMPERATURE SENDER UNIT IS AND ITS THE ONE THAT HAS THE 2 BLADES ON TOP FOR THE CONNECTION