stock tire sizing or bigger on '96 6r?

When I bought my 96 6r track bike, it came with the 170 on the stock 160 rear wheel. Now that the tire is wearing down, I need to slap on a new tire. My problem is what should be my next choice: a 160 or 170? I hear the handling will be better if I go back to the stock sizing. To be honest, having never ridden the bike with a 160 on it, I can't compare the two. However, some people suggest that it isn't good to stuff a bigger tire into a smaller wheel. To me, the 170 felt pretty stable and turn-in speed was good. So should I go ahead and make the change or stick with the current sizing?