Hello myyaz33,
I have a woods subsoiler [ripper shank & potato plow attachment] & pulled it with my 273 quite a few times. My soil is extremely hard clay, I have R4 industrial tires and I had little trouble with it.
When ever I caught a root, sometimes I'd back up and ram it forwards a few times or just raise it a tad to get over and continue on. Of course, I would go back several times along the trench to ensure wherever there was a root it got broken. Usually, I just used the ripper first - then put on the potato plow and ran my trench. It works quite well. And, of course, I always run it fully down as deep as the 3pt will go - approx 16". If soil is slightly damp, it pulls much easier of course. Here, I'd wet the area first sometimes - but not always. Just a matter of length of trench or time to get-er-in.
That and box-blade usage are probably some of the more serious strains I've put on my weak arsed input shaft though! Har! Greg