Near the end of rebuilding my 351C I realized that the heater hoze connection on the block was removed during the machine work. I can't figure out where to get a replacement. It's a straight 5/8" diameter nipple, probably 2" long including the part pressed in the block. NPD lists a 18599-1 elbow connection but I don't know if that will work. I called and they didn't know. Any advice? Thanks.