HI, I did get a Raybestos part # for a 68 T-Bird rear hose, BH381217
Also 69-70-71 Galaxie BH36633, now I don't know if the part would be the same for a 66 Galaxie-LTD, but I know all 65-66 Fords rear brake hose would be the same # for those cars with big block motors. Check this website out.
Greg Donahue Collector Car Restorations
He is the best for knowledge of parts for the 63-64 Fords and I am sure he could find where you might get a part # for your 66 LTD, also his phone # 352-344-4329. Also check Ford Parts, Classic Car Parts, Truck Parts and Services by Auto Krafters-Mustang Auto Parts too!
they are also Ford product parts, more sources...Auto Parts Fast at RockAuto
, Ford Ranchero, Ford Falcon, Ford Fairlane, Ford Torino, Mercury Comet, and Mercury Montego Parts Online
. This should keep you busy for a while. One of these outfits should have a part number. Put your pointer on the above lines and click on to them.