handling car 17's or 15's?

Get the 17's. Wide tire selection, and handles great. I have KBY shocks, SS springs out back, 1.00 bars up front, and the stock 340 sway bar. MT Street 295-45-17' on the back and Nitto 450's 225-50-17's on the front. 60's in the mid 1.6's, and with Cordoba drilled/slotted rotors up front and T-bird discs in the rear, stops very quickly.