yes, I'd say the shroud is the problem, that flat configuration will only be cooling the portion of the rad directly in line with the fan, and is otherwise stopping the air flow, especially at speed .... a shroud normally stands off from the rad and tapers out to the fan so it can draw air across the entire rad fin area .... you'd do much better to go with a stock fan
Bill
fan shroud is 3/4" off the cooling fins. tapers down to the edges of the radiator from the fan. i removed 6" from below the fan and resealed it. same results. i then removed the fan shroud and installed a huge pusher fan on the front with two shop blower fans forcing air into the radiator. all with the like results.
