340 engine mounts may be available

I've been looking for engine mounts to go from a 273 to a 340. No one has had new ones that I've been able to find. I don't want to do the 318 mounts modified either.
Classic Industries has the mounts listed on their site now. I contacted them and went back and forth with Joe Dunn from there. The mounts are on back order for 10-30 days. The ad read a little funky so I had Joe confirm these are the right mounts for the 273 to 340 conversion, and the back order delay. MN1510 is the part number. If you google that, you should see them.
I am skeptical about all this, but hope they really are able to get the mounts in 30 days or less.
I'll update this post if/when I get the mounts, and if they are correct.