Mine had an aftermarket tune when I bought it. It came with one of those handheld bully dog tuners. I never bothered trying to tune it as it ran fine to me. I never had a situation where I felt it lacked power.
Yea I have both also same year 2001 my 5.2 is a 5 speed the 5.9 is an auto. The 5.9 has a noticeable advantage in power but I love my 318 5speed. 289k miles. And still strong.... well strongish
I'm not sure how far you are from Ohio but I saw a 318 on Facebook earlier said it ran when pulled but smokes. For 75 bucks it's about 6 hours for me a little to far or I would get it myself. I'm looking for a spare 318 or 360 myself if I find one close to you I will let you know