Here is an Ebay auction for a used C5DA bellhousing by Ebay member "ssnova65" with a Buy-It-Now of $200.00:
USED Ford bellhousing with clutch fork for 1965-1970 Mustang, Falcon, Mavrick, 289 / 302 C.I Engines with 3 / 4 Speed manual transmissions. Part number C5DZ-6394-A. In good condition, will need blasted before use. Last picture will tell you more about what it fits. Do your own research before purchase !!! Selling AS/IS. If item gets damaged during shipping, It is YOUR responsibility to file a claim with the shipper, The item will have insurance on it. Sorry about the cost on shipping, last aluminum bellhousing cost me $51.00 to ship with FedEx.
1965 - 1970 FORD 289 302 4-Speed Bellhousing with Clutch Fork OEM C5DA-6394-A | eBay
-Fred-