I have a stock oil cooler with the lines from my first GN. My first GN had 5000 miles on it and this was the first stock part I took off. As you can see it still has the factory tag on it. $65 plus shipping or best offer.
This part is a factory part as my car was 100% stock down to the optional raised white letter tires. I have never seen braided oil cooler lines on a stock turbo Buick in 86 or 87. This part is off an 87 GN.
Kirban's had replacement oil cooler lines. He references the "fabric" covered stock lines. His replacements copy that but have different style hose ends. Don't know if when they built your car they were out of the Aeroquip lines and used those? Every TB I've ever seen with stock oil cooler lines were woven and replacements weren't.
Off Kirban's website:
1986-1987 Turbo Regal -
Replacement OIL COOLANT LINES (2) and O-Rings (2) KIT
These critical oil coolant lines have been discontinued from GM for several years.
We carry new reproduction replacement lines, which will fit all stock 1986-1987 Turbo Regals with the factory original radiator and oil adapter.
These have the fabric covering which GM used originally. Later models and replacement oil coolant lines from GM had a smooth appearance.
These new lines have a similar appearance to the original, but differ on how the hose portion connects to the metal tubing at each end. This difference is visible in the photo above comparing the original oil coolant lines (bottom two) to the replacement lines (top two) we offer.
The lines have been reproduced by a major supplier that specializes in pressure lines. This same manufacturer also makes the fuel lines we sell.
We only offer these as a kit with two oil coolant lines and two o-rings.