Isuzu G-series Twin Cam

Just noticed whilst putting the g200w into the engine bay the other week, where the filter is theres a flexible hose going from the bottom to the top of the oil filter mount..
I take it these lines are to run a oil cooler if wanted?

Is it worth doing ?

Personally, I would run a cooler if the fitting is there.

thank you

Any tips on how to add an oil cooler to the system?

There are three ways I've considered - making some kind of fitting to the oil filter to send the filtered oil through the cooler before being fed into the motor, but this would restrict flow unless an electronic oil pump was fitted inline.. Which could do good or cause problems...

Removing the centre of the stock oil pump, doing the aforementioned and solely running a high power electronic oil pump to suck through the cooler and pump through the engine...

Or running a low-ish flow oil pump from an entry and exit fitted to the sump, simply cooling the oil in the sump, independent to the existing oil pathway.

The first.
It shouldn't "restrict" flow.... It's what most do (Piazza etc).