This would definitely be a +1 size, which is what I'm looking for. I need to figure out if it will be a problem (other than the odometer and speedometer being slightly off on the low side).
Actually it's kinda of plus zero (which is really 275/55/19) as your increasing sidewall height but not overall width (though it too is increasing somewhat due to the overall effect of the sidewall to width ratio's as that's what these numbers really are, ratios).
In true terms a +1 is increasing diameter (20") and width with a lower profile to obtain the same overall diameter.
Tire choices may get better with the change from 55 to 60 sidewall ratios, and the higher sidewall will offer better security (for your rims), but obviously you'd have to make sure that overall load rating stays the same or increases, deal with more sidewall flex in turns, and check the clearance.
I'm lucky in that I did a +0 on my wife's last car to get better tire options and while I knew the tires would fit based on calculators like discount tire directs, the tire shop I was buying them from doubted me (they're not used to +0 combo's but were willing to match the price) and fit two tires on and checked the fitment front and rear before installing the other two and balancing them all up...maybe you can find someone to do the same...you could offer to pay them $40 for the two mountings if it doesn't work....