73-76 slant six to small block motor mounts

Schumacher made a motor mount that enables a small block motor to be compatible with a slant six k member. I’m currently working on a 76 duster and need the correct motor mounts for a 73 and up. They sell trans adapt ones online for 67-72 but those will not work with the 73-76 a bodies. All places online including Schumacher are out of the part I’m looking for. If anyone has any tips, alternatives, or the part I’m looking for that would be great. I’m not looking to change over my entire front end. It was just rebuilt. Thank you