To answer some questions (I'll try to get them all):
Pistons - I don't know. They came with the lower rotating assm when I bought the car (some assembly required). In fact, all of the lower assembly, heads, etc, came with the car when I got it (I added the roller rockers and chrome shafts later). Things like the cam, intake, carb, peripherals, etc I bought to get the engine together. Yes, it's an issue, and it's one reason I'm leaning toward hitting the reset button and starting over, so I KNOW what is in the car....but that is more money that dealing with what I have.
Fuel - What I meant was I don't think I'm going to get near the 240 everyone was expecting just through fixing the A/F issue. Fuel volume and pressure and good.
Money - My card has a high limit....but I don't like running my hobbies on credit. :D Honestly, dropping $10k on a motor, for my purposes, is silly. If I was going to spend that I'd sell the Dart, the Avenger, add that money, and put it down on a 392 Scat Pack, or even "just" a Super Track Pack R/T.
Street Cruiser - They hit 5200 on the dyno...that is probably the FASTEST that motor has ever spun in 15 years. Even in it's current state it "works" as a cruiser and fun car just fine. The fact that it's "not right" will just bug me to no end.
Yes, I know the 518 OD saps power, but turning 2200 rpms at 70mph is just NICE. I figured this was going to hurt some.
Tuning - maybe 5-7k miles on the cap, plugs and wires. Trans and fuel filters get changed every few years. Fuel tank, sending unit, etc are all relatively new.
After looking at what stock 4bbl 360s were back then (220/280), versus mine (with the lean fuel condition) the numbers are probably about right. There was definitely a torque increase, even with the 518 and the lean A/F. We'll see what happens after some carb work and general tuning.
If I know it's a least "right" maybe I'll be happy. I considered a nice little 318 instead, but then I'm giving up the low end torque that's handy for daily driving.