I recently got mine fully working:
http://67-72chevytrucks.com/vboard/s...d.php?t=631112
I find it works ok since it blows on your head. But, the heat from the engine has a slight edge towards the feet. I think a front AC addition would be great. Others have done it and have posted here, so search away. Currently, I'm leaning towards the Old Air Products, but other things are taking priority.