Head pipes

Any thoughts on going with true duals? I don't want to lose any low to mid range. I know that a crossover pipe is good, but....

true duals are good! with a good set of mufflers you'll have good back pressure....but a 2 into 1 system wil be the Best for HP, ease of tuning, and The design of a Harley Engine!
A 2 into 1 exhaust is the best exhaust for a V-Twin Motor !

If it was I'd have one on the street bikes & the race bike too, but I don't. They only work in a range approximately 1500 rpm wide, typically 3000 - 4500 rpm & all create a big torque dip in the 2500 rpm range. Not enough room here to fully explain why & I have in some older posts when the format was a bit different.

Now, for those who normally ride in the range that the 2-1 works best in, it is the best setup for them, but if you want a lot of low-end "grunt", and/or a smooth & more linear power progression from off-idle to redline, a 2-1 is not the best choice.

Below are the torque numbers from dyno runs with a 1200 Sportster, comparing the stock 2-2 exhaust, with crossover & Screamin' Eagle (Cycle Shack type) slip-ons, with a Bub 2-1 system. I'm using the torque figures rather than HP since HP is just a mathematical function of torque & more relevant to normal day-to-day riding. The bold numbers are the higher of the 2 torque figures in any given rpm range:

rpm / 2-2 / 2-1

2000 | 57.7 | 61.2
2500 | 65.6 | 52.1
3000 | 64.3 | 65.5
3500 | 66.8 | 74.1
4000 | 71.2 | 77.0
4500 | 74.6 | 72.7
5000 | 75.3 | 67.6
5500 | 74.0 | 65.4
6000 | 70.8 | 63.4

So there you have it - the exact numbers will vary from bike to bike & exhaust system to exhaust system, but the overall pattern will still emerge - the 2-1 system has a big torque dip, then comes on with a surge, pulls strong in a narrow rpm range, then fades away.

And as I mentioned in another recent post, the idea that "backpressure" is a good thing is wrong. Don't know where the idea came from & it's been around forever, but it's still wrong - backpressure is always bad.

Sorry, I've got a Road King

The laws of physics aren't any different for a Road King (or any H-D) than they are for a Sportster.