mrbones,
Is the Vintage Air heater that you have like this one:
This is the one I used in my CR Cobra. To install I just fabricated a couple of brackets out of bar stock, bending the ends of the stock to match the top of the tranny tunnel and the fiberglass in the upper part of the cowel area.
Here are a couple of (poor) pictures showing the unit mounted. Sorry I don't have any pictures of the brackets themselves (the brackets are behind the heater).
