Chevy Duty also has those mounts. You need to figure out if you have your ORIGINAL bellhousing or the bellhousing from the 54 engine. They are different. Part # for the 47-53 are 79-105. Part # for 54-84 is 79-111. Go to the Chevy Duty website and look at the photos of the 2 mounts and simply get the ones that look like yours. Then you will know what bellhousing you have. Good luck. Also LMC has a great catalog with exploded views of most of your truck parts. It's a great reference.