From what I seen posted there are 3 different supports, 2 for gas, 1 for diesel.
The gas ones are small & large openings.
Small for non-AC trucks
Large for AC trucks and I pretty sure HD cooling.
Now you can go for the larger if yours is small and get a larger radiator and a shroud.
The non-AC radiators did not have a shroud but a little fan cover at the top.
Now I think it was on the older trucks they all had a large opening and if the truck had a small radiator they used an bolt in filler panel. I guess you could do something like that if you wanted to.
Dave ----