I dont have any history for buying a radiator but have a suggestion for your power steering box. It is a steering box from a 92-98 Jeep Grand Cherokee and it is a straight bolt in using a pitman arm from a stock power steering unit. It gives you 3 turn steering from pin to pin. I installed one about 4 years ago on my 64 and have been very happy with it. Very simple and cheap to do with lots of help on the internet. So simple an old carpenter can even install it. Just needs one custom made hose to go to your pump. Am willing to answer any questions you may have if interested.

A body Chevelle steering box should be the same. Available at most Auto stores, may be a core required. Upright style rads are available again A body

Thanks

My old 65 Beaumont had a steering box from a Z28 supposedly , it worked fantastic and would like one in my current 65 SD.

Almost any 3 bolt GM PS box will fit. Later boxes in the 80s have metric fittings but you can get sleeves from Lee Manufacturing in California so you can use your original hoses. These later metric boxes are the ones which use the mid 80's rag joints. I once put a Buick Grand National box in a 68 Impala, using the impala pitman arm and the pickup truck rag joint that Jerel mentioned. I have the part numbers for all of this stuff. If you want the info let me know; I can dig it up for you. I also tried a 70 Z28 steering box in the Impala, approx 2.5 turns lock to lock. It wasn't great for a full sized car but it would probably work for a Camaro, Nova, Chevelle or Beaumont.

Good choice if it's from a v8 Jeep. Will need the sleeves and the later rag joint I believe.