what's your gearing now? 1 tooth down will not equate to 6-7 teeth up in the rear as most sprockets work in almost a 1 front to 3 rear ie 15 tooth front and 45 tooth rear is somewhat common and most stock sprocket sets are within a few teeth of that. Front or back shouldn't matter for stressing the chain if you only go one down front or 3 up rear. It becomes a small problem in the front when you go down 2 or more teeth as the radius the chain has to go around is soo much smaller. Only one tooth down in the front should give you nearly(70+ %) the same chain life as stock. With going up teeth in the rear you have to worry about the material of the sprocket as many rear sprockets are made out of pure aluminum which will wear much quicker than its steel counterpart. If you do go up in the rear instead of down in the front try and buy a kit or rear sprocket thats hardened or made out of something besides strictly aluminum just so it will last a little longer. You will notice a slight difference when riding as it was immediately recognizable when I went down one tooth in the front.