There are two different big block radiators. One is 34 X 18, the other is 34 X 20. Two inches taller. With the taller one you need the the taller upper shroud if you keep the small block. If it's a big block you need the big block shroud. The big block fan sits higher so different shroud upper and lower. Taller rad also has "Z" shaped upper metal mount plates and the filler over grill area is step shape.
You can get a high capacity radiator with oil and trans cooler and 2.2 core, 3 row , 34 X 18, with a TYC # 624. This size is installed with factory big blocks. The bottom rubber mounts , pull and reinstall in outboard holes. Same with upper plates, move to outboard mount holes, for production runs their already in place. You may have to bend or trim the side sheet metal ,on the earlier year. On my 93, I had to bend a little on the sides. On the 95 and 98 it was a drop in. You my have to get an adapter for the trans cooler lines. A male inverted flare adapter , common got mine at O'Reilly's off the shelf. The shroud you'll have measure. All three of mine had 34 wide radiator, so drop in. Economy wise I would think there is small block and big block tall shrouds only. Why make a separate narrow shroud, just make millions same size. But that shouldn't be a problem , even at treasure yard.
It gets above 100° F for weeks at a time here. So I wanted a good high capacity cooling system. I also installed the factory Aux fan and a power steering cooler I got off an HD at the treasure yard. Once all three trucks get to operating temp even in hottest July I have no high temp issues. Good luck!
