I am facing the same issue on a 89 truck. Existing small transmission oil cooler is in front of the radiator. Am considering buying a cooler with an intergral fan. Then I can locate it anywhere under vehicle, and not in the frontal grill area. I agree that the radiator needs all the cool air it can get. A bunch of cooler in front of the radiator hurt engine cooling.
83 C10 Suburban, Silverado, 6.2, 700R4, 3.73, 31-10.50R15
82 C30 Crew Cab dually, 6.2, Banks, Th400, 4.10, Gear Vendors, 235-85R16
83 C20 Suburban, Sierra Classic, 6.2, 700R4, 4.10, custom paint, 285-50R20
95 Yukon, 6.5, 4L80E, 3.42, 265-50R20
73 GMC Astro 95, 8V71, 10 speed Roadranger, 110" WB, 6 each 11R24.5