load ratings?

[equ]

The rear summers on my 340i will need replacing soon (they are down to 5/32nds or so). They are PSS, not the latest and greatest PS4 but they suit the car fine and the fronts have a good amount of life left (staggered).

A pair of right size tires with lots of life left have popped up locally. I guess the 255/40/18 size that is a rear for my car is a front for some kind of AMG merc. I'm very tempted to snag the pair... But here is the dilemma, at the last moment, I noticed that my tires are 99Y and these are 95Y.

I'm thinking I can get away with this by simply keeping on top of rear pressures and making sure not to overload my car. I currently run 33 front and 35 rear and generally the fronts heat up more than the rear as car is an xdrive with something like a 52/48 distribution.

Or should I be a stickler and pass until I match the load rating? Never going to see the track.