I've got 1997 5.9L/360ci with a little over 180,000 miles on it and I'd like to put a performance cam in it, but I dont know if doing this with as many miles as I have is such a good idea. It has all original stock parts as far as the heads,intake manifold and internals. But Ive replaced the clutch fan with an electric fan, installed headers,CAI,and programmer with the 160* stat.

As far as the type of cam, I'm thinking of a mild duration that will chug while itleing. I'm not sure what size cam would do this! Your opinions are wanted!!!

 

If you have taken care of the engine, you should not have too many problems upgrading now. A mild cam with a tighter valve overlap will get you a decent improvement in power. You might not realize a huge gain if staying with the stock heads tho.
The cam only idea is probably safe, do more and you should think about some new rings and such. Let the budget be your guide...