Looking inside the intake port of cylinder 6B on JagZilla's original motor. I ported these heads myself in 2001, after reading a DIY article online. Although this is a slightly different angle than the photo of my GTJ port, you can see the port opening is matched to the gasket opening size, and that there is a significant difference in the amount of material surrounding the valve. What isn't apparent is that the port is significantly larger all the way down to the valve head, and that the sharp inner radius has been smoothed out, creating a much gentler curve toward the valve head, and greatly reducing the bottleneck which is present in the stock intake ports. If I remember correctly, each of my ports now average 39mm for the full length of the ports. I believe the stock ports are 33mm but, are considerably smaller than that where the port curves downward to the valve head.