Actually, if you do get through to Griffin, and send them all your dimensions, they'll probably take a lot of your $, laugh at you after you hang up, and then send you one they already have on the shelf: Part #25135. While this will only fit Mantas and Asconas, Summit lists it as part # GRI-2-25135-X for $221.95.
http://store.summitracing.com/partde...4&autoview=sku
If you were going to Carlisle, I'd sell you a set of mounting brackets there, as I plan on taking some for sale, along with some for a similar radiator for GTs and Kadetts. If you're not in a hurry, and want to make your own brackets, there should be an article on the whole project in the Blitz in the June or July issue.
(If you are in a hurry, don't want to make your own brackets, and aren't going to Carlisle, PM or e-mail me and we'll talk details and price.)