Here is an Ebay auction for a used rear end pinion snubber bracket by Ebay member "toobadmustsell" with a Buy-It-Now of $999.99:
VERY RARE AND HARD TO FIND, FORD 9" REAR END 3rd MEMBER PINION BUMPER SUPPORT BRACKET with original rubber bumper, will work with 1965 1966 Mustang and others that came with the 289 K HI-PO engine, I have been told that the 1964 and some early 1965 are not the same as this one, the side on the right goes straight down more, I think its more of the time or date the car was build, metal bracket is nice with a few light pitts mostly on one side, the original bumper shows some wear, has been cleaned and bead-blasted and painted with cast paint for that factory look and ready to install. Please look at pictures to determine condition and ask questions..Look at other items up for auction, Will combine shipping to save you money
FORD 9 REAR END 3rd MEMBER/PINION SNUBBER 289 K HI-PO 1965 66 MUSTANG,FAIRLANE | eBay
-Fred-