if you put a 190 degree thermastat in it, it will get up to that temp. [ they can stick open] the chrome rings can be very tough to seat... even moly rings need a proper hone job to seat quickly . what oil did you use to break it in? probly best to put a moly set in it and rehone... there are a pile of tricks from the past to attempt to seat them but I would bite the bullet on the rings if the leakdown test confirms it.