Mine has an HIO-360 in it. It came from a helicopter and is rated at 210hp but since I can't pull all the RPMs, it is 180hp officially. And yes, you can run out of rudder, especially with strong crosswinds from the left.
Budd Davisson's pieces are good starts but remember, Swifts are like snowflakes, no two exactly alike. Different engines, props, hyd pumps, gear doors, seats, canopies.
The airplane started off with an 85hp engine which some said was just enough to get it to the crash site. Over the years, it morphed into a different airplane including one version that competed (and lost) to the Beech T-34 as a military trainer.
It is not difficult to fly but it does keep your attention focused especially with gusty crosswinds. I keep mine at an airfield noted for crosswinds and like the owner in Davisson's article, I watch the windsock intently. 25kts direct cross in the jets... nothing to worry about. 25kts and gusting and in the Swift.. it gets my attention.
Best bet is to fly a few of them. You will also hear all kinds of stories about speed. A wing is a wing is a wing. Some have had the slats covered and some have some mods to the wing but I flt plan around 130kts (I wish it was as fast as it looked) but that is at around 9gph. I have the standard tanks with a 9gal aux tank so I can easily do 3hrs.
I do not have an autopilot so I am constantly engaged with it. There are a lot of good things to say about the Swift and it will bring people out every time you land. It is a conversation starter. But don't plan on carrying a lot of stuff (little room under the hat shelf).
This is always a good illustration. The Swift had some designers on it that also worked on another airplane and you can see the similarities. P-40 on top. Swift on bottom.
Good luck and let us know about your impressions after flying one.