It really depends on a lot of things. Most importantly is how you wheel. I run 37s on 5.29 toyota third members and I am not a ginger wheeler. However I am also not an idiot or a thrasher. If you are smart and don't try to force your truck forward in situations which are going to break something. Then they absolutely can handle 37s. Low gearing, good spotting, and experience are going to help you keep from breaking. Also if you haven't already upgrade your birfields to RCVs.  Start thinking about upgrading your outputs soon as well. That is next for me.