Hi PSKSAM2 and welcome to FTE

Are you thinking of doing the timing chain just because? Or is there a problem?
According to the Ford <a href="http://motorhaven.autoanything.com/">shop manual</a> you can do the oil pan without removing the engine but you have to remove the front diff assembly and then lift the engine up a ways.
The manual says to remove the oil pan to remove the timing cover but I'm not sure that you really have to. The oil pan gasket might stay in place ok and with a little dob of silicone in each corner you might be ok.
I dont remember ever seeing a timing chain worn out on a 3L. I'm not positive but I think it is probably a double roller chain and even when they are falling off loose they still dont jump.