I don't know if there's data on how a 176-->180 taker performs in admissions cycles, because I think most people with 176s aren't silly enough to retake, but again, I think it would actually come off as a negative soft.
At any rate, if you were asking us for advice, then I think you've gotten a pretty clear consensus.
ETA: Also, is not this discussion a wee bit premature anyway? Am I correct in thinking that you are still just, like many of us, waiting on a JS2?
I am waiting on a JS2, but there is nothing I can do now to impact my odds for this year, so I'm thinking about ways to improve the next time I apply should it come to that.
I am a little surprised at the response here. I thought the consensus on the LSAT boards was more or less "always retake," I am unsure why that would be any different at the high end. Yales 75th could easily be 177 this year, and if that is the case there is a clear advantage to even a 1 point boost. I don't think I have a really good chance at Yale anyway, but nonetheless I think it's a little strange that doing everything possible to improve an application would be seen as a negative, as it clearly is here.