The minivan 3.1L had the iron heads, But the problem is they used DIS ignition. It won't fit because the intake will hit the distributor used on the Fiero 2.8L.
It has the same problem as the 3.4L intake used on the F-body. The intakes need to be modified to provide clearence around the distributor.
The aluminum headed 60* V-6 intakes are not interchangeable with the iron headed 60* V-6 intakes.
[This message has been edited by Oreif (edited 05-20-2008).]