My mounts came with my 302. John York built my engine.
http://www.kitcar.com/york/home.html
His phone number is on the website. Try giving him a call, he is located in Virginia. John is very familiar with Antique & Collectible cars. Mention the engine you are using, he may be able to help.
I believe that the mounts are just Ford products. Try a local Ford dealer.
Good luck on your build! have fun, take a lot of photos. Wish I had taken more.
Keep us updated on your success in finding the mounts. I would be glad to help more if I can
Regards