Ox tails and black eyed peas help?

Okay I plan on cooking black eyed peas in the crock pot and throwing in some ox tails. Though What would the cook time be? Also is it okay to put frozen ones in there? I've only made beans in the pot that were non frozen in the bag that you have to soak overnight. I'm thinking about 3-4 hours but I could be way off lol. It took about 6-10 for the non frozen ones. I am guessing around 3-4 because it says to boil them for only 34 minutes.