Here's a photo of Joe Alexander's Heat Shield, available from TRF or Moss. It seems to me that the car ran better this summer w/ it on, but I'd done a lot of other things to it as well, so who knows.... It is a very well-made piece.
As you can see, my new K&Ns are a little close, even with new motor mounts, so I'll be getting wedge-shaped K&Ns in the future...