Are these the wrong swap mounts for a Magnum?

Happy New Year FABO! I had some time to get to the point of no return on my Slant to Magnum conversion today. The slant is out and I modified the driver's side perch as per the instructions on the Schumacher kit. That all went fine, but when I started to bolt the mounts to the Magnum block, that's when I ran into a problem.

The engine is a 5.2 Magnum and this is what i ordered because I read somewhere (hopefully correctly) that the Magnum engines use the 340/360 mounts. It's a little hard to read because the UPS sticker pulled off some of the ink, but it' says "73+ A,B,C,F,M,J-Body Slant 6 to 340/360"
Mounts 4.PNG

Here's a photo of the page from the instructions showing how the mounts are supposed to bolt on
Mounts 5.PNG

The passenger side went on just fine
Mounts 6.PNG

But the driver's side mount doesn't fit
Mounts 8.PNG

I can attach it like this, but there's almost 3/8" of gap at the forward boss
Mounts 7.PNG

If it's as simple as buying/making some spacers and getting a couple longer bolts, that's not a big deal. My concern is that the mount won't line up with the perch in the K-member. Should I have ordered the 318 conversion mounts instead? I'll try calling them tomorrow, because I'm sure they're off today. Any advice would be appreciated.