I have a 3 core radiator replacement radiator in my 51 pu,62 261 engine.The top tank sticks up 1 inch higher than the core support.I repositioned the brackets more like on your photo the the older radiator for fan clearance.Drilled out the spot welds and carefully used short self drilling screws for reattachment.Using a 5 blade 16 inch GM fan of unknown origin with the 3/8 spacer,clears the radiator by about an inch.When working with a mixture of engine parts you may just have to make the parts at hand fit the way you want.
