Oil Cooler Install VFAQ
With Some pictures - by Martin Check
How to:

First, you should either drain your coolant, or be ready to plug up your coolant hoses going to the stock oil cooler.  Now you can unplug the coolant lines from the stock oil cooler, and find some way to block them up.  I used a metal pipe to form a bypass for where the stock oil cooler used to be, so the coolant flow has the same path as stock. 

Next, remove the stock sandwich adapter.  The stock coolant based oil cooler is sandwiched between the block and the oil filter by a long bolt, so all you have to do is unscrew that bolt, remove the stock oil cooler, and stick your Derale thermostatically controlled sandwich adapter in its place. 

Screw the stock bolt right back into place.  Since the sandwich adapter is the exact same width as the stock oil cooler, the stock bolt should fit perfectly.  

You can then use the supplied barb fittings with AN-8 Aeroquip hose (no messing with expensive/fragile aluminum fittings), and mount the oil cooler whereever you see fit.  In these pictures my oil cooler is where the stock sidemount used to be, although I've since moved it near the ABS unit on the driver's side. 

Once the oil cooler is mounted, run your lines to the oil cooler, trim them to the appropriate length, and mount things up. 

You'll need to use a WIDER oil filter, as the sandwich adapter outlet is bigger.  I used the Fram FM3950 oil filter, which fits perfectly.  Theoretically any dsm big filter will work (91 and earlier), which includes: FRAM 3950, TVI V-193, Purolator L10193, Wix 51381, Casite CF-2856, Hastings LF-144, Champ labs PH-2809/2810.  However, I tried the WIX 51381 on my car and the gasket was too small and thus leaked, even though the filter itself was the same size.  Try non-fram filters at your own risk (wow never though I'd say that). 

Finally, pics can be viewed here:

Note the oil spill, which actually is from my turbo oil feed line, not my newly
installed oil cooler as I initially feared.  A word of warning for all: Don't route
the turbo oil feed line behind the turbo where it is subject to massive exhaust
heat, but route it in front of the turbo!

If you have any questions, or need more details, feel free to contact me. 
Parts you need:
- Setrab oil cooler (I used part number 119-8)  - $100
- Two 90 degree AN-8 Earls AUTO-MATE hose ends to mount on the oil cooler - $20
- 3 to 6 feet of earl's AN-8 autoflex SS hose $40
- I initially used about 6 feet to mount in the passenger side
- I then reinstalled a sidemount, and managed to cram the oil cooler in next to the ABS
- It would be cheaper for crappy rubber hose, which I don't recommend, rubber hoses tend to burst... ask me how I know
- Use the brass fittings that come with the sandwich adapter, optionally adding 90 degree adapters  - $0-40 (if you go with earls)
- Derale thermostatic sandwich adapter P/N: 15702 - $30 alone, or $60 as part of the Derale oil cooler kit from Summit Racing
- Oil Filter - $5 - FRAM 3950 is the only proven to work

Total cost: $190
Total time: 60 minutes
Jeremy Ho's Oil Cooler mounted on the driver's side (no, he doesn't have ABS) - 1995 GS-T