The baronetric pressure might have changed. Along with the ambient temp. Don't be afraid to richen it slightly to compensate for these changes. That will knock the temps back as the fuel actually helps cool the motor. As well as a lean motor fires hotter. That's why when a racer uses a nitrous system, it's crucial they not lean the motor out. Otherwise when the nitrous hits, it will knock holes in their pistons. Seen that first hand on a stroker 400 smallblock.

So just fatten (richen) it up some. Good catch on the temps rising on the motor.