Your 110 set will work. Since Harley switched to the 110 for CVOs a long time ago, I'm sure people are putting 110 CVO take-offs on their 103s.
What year is your 110 set?
Have you gutted the catalytic converter out of your pipes yet? That's the biggest restriction in the factory exhaust system.
No, haven't gutted the header and plan on keeping it stock. Not wanting to change backpressure much but wanting a little more exhaust note.
I have stock 2014 CVO cans with stock baffles off a 110 ci engine on my stock head pipe with cat. These muffs flow well with correct back pressure up to around 100 hp. After 5k they have gotten a bit more throaty but are still mild and not too loud for cruising. The cat is not as restrictive as some believe as it is a honeycomb configuration instead of the old pellet style. If the CVO cans flow well enough for a beefed up 110 they certainly will work well on a 103.