I'm about to install Perma-cool oil tstats on my 468's. Anyone with experience on this? Need help how to attach/bolt it to the block? Some special bracket maybe?

Depending on your oil cooler, you may be able to rig it with a fitting where it hard mounts to the inlet side of your cooler. The t-stat will have a port that goes to the cooler, one "from the cooler", one from the engine, and and one back to engine.