What K Member and Transmission Mount ?

I just removed a 400 from a 74 Duster that has a spool mount K-member. It was attached to the block with some kind of OEM mounts that bolted to the block and dropped down on the slots. Haven't even researched exactly what I have, but I do know it fit like it was suppose to be in there. I am going with a 440 and a motor plate when I put it back together. I'll post a photo today if I get a chance to show you what they looked like.
Tom