First thing is to get on the scales so you know if you need new wheels with higher rim specs or not. 65lbs may or may not take your weight at the tires. 8,600 lbs for four 2,150s (but that assumes equal weight sharing---does not happen that way--some tires take more than their share and others less--as seen on the scales if you get the chance to check for that)
If the door says RGAWR is 8,000 and you are at 8,600 and your tires are at 65, you are there for tires, but perhaps not for springs. It is all fingers crossed because we do not know how much "margin" we have so we can say how much "over" is still ok.
Then all the forum guys start in as to how much "over" is ok as far as they are concerned, which does not help you at all. :)
My solution for being a "little over" :( is to take it easy driving, but ignorance is not bliss--know your weight, don't guess. Then you can figure out what to do or not to do.