255/50-16 (26" tall) and I was pulling ~106 mph traps last week, and I was left with that "shift or not to shift" dilemma too... I was pulling redline or close to it right around the finish line.
(285/35-18's are 25.85" tall in comparison)
Z-Jay Edmonton Z Car Club 93 300ZX TT - Stage VI 01 Sentra SE - daily driver