Glad I got some thought going about this swap. A/C does mount exactly the same to the block as any 4.6. P/S doesn't look like a big project at all. I don't see any reason why the OEM PCM and harness from a donor car couldn't be modified to work, even with the 6R80 trans. Yes, the calibration will need some work so it doesn't look for things like the cluster in the car that it came out of, but no big deal there. The 6R80 has a lot of good qualities, the one worst thing about it would be the extreme first gear, it's a bit over kill. I put it like this the other day:
We run a 3.31 axle, you'd dismiss that as being a minimal amount of gear. Well look at the overall gear ratios in the first 3 gears.
13.8 7.75 5.03
Then I compared this to a C-4 with a 5.13 axle which you would call an extreme amount of gearing.
12.62 7.49 5.13
Let me try this again, with a 4R70W, I haven't looked at these numbers previously.
14.56 7.95 5.13
Wow, that's a lot of gear in first. I thought the 6R80 was bad. 2nd and 3rd are pretty close. The large RPM drop on the 1-2 shift is the worst thing about the 6R80, but the 4R70W is worse. The best thing is having extreme gearing like this to get down the quarter mile, yet still having 3 more gears on top of that, so you loaf down the highway with the 3.31 gear and the 0.69 6th gear.
Now, what have I gotten a car to do with that wimpy 3.31 gear? How about email@example.com? Stock engine, just has headers, Boss intake manifold, useless CAI. The car has a good converter in it, a little suspension work, good tires on it. Weight is just over 3500lbs with driver, not too dissimilar to a MN-12.
Then the green car in this video is probably around 3700 with driver. The engine is untouched. The car has an offroad x/catback, alum driveshaft, wheels/tires on the rear only. Still the stock 3.15 gear, stock trans/converter. The silver car in this video has a little more, not yet finished with the tune on it, ran out of time last weekend.
These runs were made at 1300' DA, not at some coastal track with mineshaft air. No reason you couldn't do this swap and run like this too.