ive been told to steer clear of the aluminum radiators due to there lower cooling capacity! believe it or not, they actually dont cool as much compared tot he standard 4 core brass/copper units. the aluminum tubes are over 1" in diameter to provide better flow but cool less because of the tube size. less air flowing over the hot coolant. ive read and found that the 4 core a/c units offer the most optimum cooling. these standard brass/copper units have smaller cooling tubes(3/8") allowing more air to flow over the hot coolant versus the aluminums. the standard copper/brass units cost half as much and offer almost the same efficiency as the aluminum units when compared. this is again from what ive read and been told by the experts! ultimately its your decision but i would go the 4 core copper/brass unit with a/c. the added benefit is negated by the price tag and if done right your standard unit can/will coll the same or better!