The '94 Cobra has the GT40 heads with 1.84" intake valves and 1.54" exhaust valves. They also have stronger springs. They used Crane roller-rockers. Crane calls them 1.70:1, and Ford called them 1.72:1. The GT had 1.60:1 (or 1.59:1 depending on what info you read).
Regardless, it's great car. Mine will be 12 years old in a couple of months. It still runs as well as it did when new.