My side oiler is all cast-iron, 500HP, and it gave me overheating fits until I sorted out that I didn't have enough airflow through the radiator. After installing a high CFM 2-speed fan, all my problems went away. As an example it has been consistently at or above 100F PLUS humidity here in Houston since May and the car has not overheated or even shown the signs of wanting to. Me, on the other hand.....well I do get hot sitting and idling in the car with those ambient temps. The car though idles around 195-200F MAX and as soon as I start moving it drops back to t-stat temps of 180-185F. I ran the Big Bend Open Road Race in April and the temps on race day were 95F. We ran in the not-so-fast 105mph class and the car never got over 195F.
Oil temps without a cooler were about 230F.
I have almost 8k miles on my car and its been on the road about 2.5 years. Its very street able and low-maintenance for how powerful it is.