What make and model oil cooler is on this bike?

Anyone know? Also, as long as we are here: what forks are those that lose the leading axle feature on the 1981 GPz?
 

Looks like a ZR550 cooler.  It will block the mechanical tach cable, so be aware.

Thank you.

With 2023 motorcycle oil the cheapness of same and the fact that I am not riding the miles like I used to I am really wondering if the GPz550 motor even needs an oil cooler. I wonder if that would require a KZ550 oil pan or can the cooler line ports be blocked off?

Winter in MN. Plenty of time to ponder things.

Removing the cooler won't make any difference so why go to the trouble and expense of removing it.
If you want a "marginally " quicker warm up in winter just zip tie a cover over the cooler matrix to block the air flow and it's a simple job to reverse it if you need to in summer..

Long story short, advise I had from my friend in Japan. I live in Hawaii, so any cooler is a must.

Just tape the cooler at the front. Back also works, but wind usually push the tape when up to speed.

BTW, for me, I had a overkill oil cooler when I had a 85 AE86 (Toyota Corolla). Rather than taking it off, I just tape half of the cooler vertically and took them off when got warm. Just few month of the year so worked out perfectly. I think it was 15-row cooler. Sold the car but still have the cooler somewhere............

It is not about 'needing' and oil cooler.   It is ALWAYS nice to have it.,,,,on anything that runs hot and needs oil.... being air cooled or liquid cool, does not matter.    Newest high performance motorcycle also have oil coolers......air, or by coolant. 

 and it is not about 'cooling the engine" either as most people think, it is about keeping the oil as cool as possible maximizing lubricity, and not boiling.  In a motorcycle the oil, in addition to lubricating the engine, lubricates the transmission, and also cools the wet clutch, therefore picking up more heat than in an automobile (that's why is rated heavy duty, as in Diesel engines)

The motorcycle will run w/out it, and so would an automatic transmission without its oil cooler, but it certainly extend the longivity of both having it than not.

....I would actually get a GPZ or Zephyr 550 oil pan (if does not have it) to have it done properly.

<<.I would actually get a GPZ or Zephyr 550 oil pan (if does not have it) to have it done properly. >>

What model GPz came without an oil cooler?

Answer: none.