Anybody make a factory cooler? Plenty of aftermarket ones but would like to replace the one on the car with a factory one(new engine),

I don't think so. I needed one and found a great used one in the for sale area of this sight for $60.

AFAIK GM has long since discontinued the oil warmer that came on the motors in these cars.

If you want an oil cooler, get an aftermarket one. If you want a "factory" oil warmer, .... and aren't interested in lowering your oil temp but rather just stabilizing it to the coolant temp, and don't care if it leaks water, ..... ,,,, ;;; .... go used.