Once the engine and transmission are removed, you notice all the room. It's huge. The framerails are about 4 inches wider than the previous Mustangs. For years to come, racers are going to love this car. It has enough room for a nice Boss 429 with headers well inside the framerails. The engine mounts differently from our Fox body. It actually uses a single stud and biscuit setup like the old Flathead Fords had in the '30s and '40s [Robin was there, so take his word for it-Ed].