I fly in north Florida mostly. I have an 8 with an IO 360 with the larger oil cooler. I have no problem with oil temperatures at altitude, but tooling around the county on hot afternoons below 2000 feet, I'll see oil tempertures near 225. I am seriously thinking about moving the cooler to the firewall with a 3 inch scat tube to supply air from high up on the baffle behind the number 3 cylinder. My setup is currently on the baffle behind the number 4 cylinder. It would be best to not have to worry about oil temperatures, so I recommend you buy the larger cooler and mount it on the firewall. My baffles are sealed very well and I never have CHT problems; just oil temperature. Good luck.