OK, my friend with his Cozy IV (like a Lancair, only slower), IO 360 powered, finally replaced his Natasha...Naomi... Niagra.... cooler with an equivalent Stewart-Warner and, even though the air pressure across the cooler dropped (< 5", better air thruput?) his full power climb to 10,500 never saw the oil temp go beyond 215.  I, of course, had to reduce power (both throttle and rpm) so he could keep me in sight.  His cruise temps dropped back to less than 180, a number seldom seen before.  So, anyone looking for a nine vane nonSW cooler for a low price, let me know.