i made a similar move with an old DELL. using the same HSF, expect to see idle temps in the low 40s and load in the low 60s as that chip runs hot. those temps are considered warm for a CPU but still within its ability to operate properly.
That raises a related question: How do I tell what temp my parts are running at? It's something other than making sure I had adequate cooling, and cleaning out my comp every few months I've never really looked into, since it was all stock equipment. So, I assume it would function appropriately.