This list of CPUs and their sockets shows you would be limited to two very historical CPUs indeed, the 8088 and 8086, if you use a DIP40 socket.
Neither of those are 486-based, nor will they will execute the full 486 instruction set. To run the full 486 instruction set, you'd need a PGA socket (of which there are many, listed in the first link in the first sentence) or a slot (op cit.).
I was repairing PCs, and teaching dealers how to repair them, back when CPUs came in slots, and I will tell you PGA sockets gave us a lot less trouble than slot-based CPUs.