Well I've decided to go ahead and build a prototype. I'm building the necessary frame work out of timber battening, the idea being that if I don't like the look or if it doesn't improve cooling, I can put it back to standard. I do have a 3.2 engine I can drop in.
Here are pics of the framing of the duct to the radiator before I encase it with ply. I have plumbed into the waterway, from the radiator, the temp sensor that cuts in the electric fan and also an accurate digital thermometer probe.
