This 2 ton car needs the power of the cursed 3.5L six (176 HP).
A 3.0L six at 148HP may be sufficient - if you're not an aggressive driver. It's a good engine and may be worth the effort to find and install. It's reliable but can't be overheated so keep that in mind, especially if you're driving involves long hill climbing in hot weather. The car will then have a "story" - a smaller than stock engine - but at least it's a good engine - not the cursed 3.5L!
Otherwise, I'd just fix the old 3.5L and drive it for another 173K miles when the rest of the car will be ready for the bone yard. I believe the new connecting rods are heavier so there's hope for this fix to be permanent.