I probably would gear it down a tooth on the top. If your riding in the same conditions/elevations as before, then your clutching should perform about the same.
That said, beacuse of the slightly added load and more traction in deeper snow adding another 10 degrees of twist in the secondary spring will improve belt pinch and backshifting.
Also a 43-39 helix works well with larger tracks and off-trail riding!
Bill