I just purchased the Kohler Seaforth cast iron 54" tub. My alcove is 58 and7/8". On the tub specs there is no size specified on the size of the outlets. I call Kohler and I'm told outlets are 2 and 1/4". I was planning on using the Moen rough out kit and the Moen drain kit (2 piece) drain and overflow cover. There are no size dimensions for the exterior dimensions of the tubes that goes into the tub. I call Moen and I'm told they are an 1 inch 7/8. None of this seems right to me. I thought they are "standard". I could just use the recommended Moen K-7213 unit at $109, but I don't want a mechanical drain. We almost exclusively shower so I want to save a few dollars and avoid mechanical issues. Doesn't it seem like the Moen rough out kit will work. Any other suggestions. Thanks