Hey there! I have a 1994 t/a with after market 17" rims I'm wanting new tires and wanted to know what would be the widest and tallest I could go? Or any suggestion I have 275/40zR17 on right now and wanting a bit wider maybe a little taller

 

If by "taller" you mean a larger outside diameter you will need to reprogram the PCM for the new tire diameter, or else your speedometer will read lower than actual speed.

How wide you can go on the tires depends on the width of the wheels. What is the width? 285/40-17's are getting harder to find. 315/35-17 would match your current diameter, are getting harder to find, and typically require at least a 10" wide wheel.