PONTIAC ALL MID SIZE (GRAND PRIX, GTO, LEMANS, ETC.) 1964-87 Metric: 5 X 120.7
Standard: 5 X 4.7514, 15 7/16-RH or 12 X 1.5 70.3
taken from my favorite lug pattern site in the world. once again, its a hub cap, sorry to say its a 5 lug wheel.
Wheel Bolt Pattern Cross Reference Database and Conversion Guide: 5 X 4.75