I have a 2011 Yukon XL 1500 SLT with 5.3 and the radiator looks to be leaking a bit on the drivers side so looking to replace it soon. From what I see I have the RPO code K5L which is the enhanced cooling package. The radiator appears to have both the transmission cool and engine oil cooler. On RockAuto the genuine GM part # is 21742 and it's about $430 (O'Reilly wants $777 and it's not in stock/special order). That radiator has a core thickness of about 1" (1.07). I have had some issues with it getting hot going up big hills with the AC on so was looking to possibly upgrade it. The only ones I see with a thicker core are a OSC for $174 and a FVP for $155, however for those prices I'm leery about how good those are, they also have plastic tanks and I think oem are metal. Anyone have any recommendations for a better radiator?