looking for 5.7 to /6 k mounts....
Basically you have two choices. I know because I also have a '67 slant six car.
1. Make your own.
2. Swap out your K-member, and use the TTI/Schumacher mounts.
I have a complete blog posting about mounting options here:
http://drhemi.blogspot.com/
FYI, I was able to find a 73-76 K-member on FABO for 100.00. Good condition for something pushing 40.
Regards,
Joe Dokes