Yes, the right one. As usual, the other two couloirs are two thirds snow and ice and one third dirt and loose rock. There is something special about the right couloir on North Peak. I've done it twenty-something times, and it's always in good shape. Many of the other Sierra couloirs melt out or drop tons of rock. Split, Gilbert, Thompson, Mendel, North Palisade, and many others are hit-and-miss, at best. North Peak may not have the ratio of ice to snow that you prefer, but it's always a good climb. It's at least two thirds névé right now. It's lots of fun, but it usually has much more ice this time of year.
No, I didn't bring the inclinometer. It was 45º-46º when I measured it back in the early 90s. Despite you-know-who claiming that it changes by 20º depending on snow depth, it's still the same.
Go do it before another storm covers it up and closes all the roads until June.