My 2 cents: is upgrade to the biggest aluminum radiator you can fit. In my case I custom designed with a rad company to fit into my available space. Off the shelf did not work for mine but its a different chassis than yours. Thats the first part. 2nd and third part is Then install the biggest fan(s) you can with good shrouding. I also learned to not to use aluminum radiators whose tubes are epoxied into the core, mechanically brazed into the core is more durable over the years. Shop carefully.
Motors are just too expensive to screw around with old tech radiators A good custom built shrouded aluminum rad is about $800, good fans $200 then a good controller if you desire $200. All cheaper than a new motor or even just a head gasket job depending on the damage. Dont take my word for it, call some noted radiator experts to get pricing and solutions. My 475 hp big block can idle in 95F summer heat at 200F, with both fans blowing. The downside was having to upgrade to a 140A alternator to feed those fans.
