FWIW, I had my oil cooler in front of the radiator for a long time but deep in the summer my water temps ran high(per the factory gauge). I put an oil temp gauge in and saw some high numbers as well. I moved it to the right side, buggered up a nice big hole, much bigger that 4 inches and still had high temps. We moved the cooler forward a bit to help the air from getting packed in behind it, put a two hole scoop in the turn signal and one hole scoop in the foglight hole, ran some brake cooling hoses to the cooler and now I can barely get to 210 degrees even on a 100+ degree day! I still run the factory water temp gauge for now but it generally runs in the middle in the summer unless I'm right up behind someone