There are a couple of answers. The short answer would be yes. Some people love to stack Testosterone with LGD 4033 SARM. Also, people are talking on forums about how they are stacking Trenbolone steroid with GW 501516 SARM.
For the longer answer, you can stack, but the more stuff you stack, the more your testosterone suppression will increase, which means you will need a longer course of PCT treatment.