I'll be the contrarian - I think you will bend or break the KK subsoiler in the first 30 minutes of use with a 55hp tractor and rocky ground. The KK subsoilers I have seen do NOT have a shear bolt or any other form of protection. I have easily damaged much higher quality equipment (Landpride) rated for 50hp with my 50hp on the dot tractor (JD 5105).
If you decide to try it anyway, I suggest operating in 2wd to increase the chance that obstructions will stop the tractor instead of ripping the implement apart.
Please report back, I'll be curious to hear. I suspect TSC will replace it the first time it breaks and not the second. Me, I'm tired of replacing draft pins on my supposedly rated for 50hp landpride scarifier (it's not just the pins, either, part of the frame - 3/4" thick - has bent too). If I did it all over again I would get a high quality subsoiler from someone else, with a shear bolt protection.