High compression timing issue.

It's not an Abody. Buf I have my '69 d100 pick up. She has a 360 stroker (408 CI). It was a crate motor from bluprint.. Compression is 10.1:1. It was a pretty recent purchase that I made, so I dont know a ton about the truck. Recently I started hearing a knock from the drivers side of the motor. Shes been running full synthetic royal purple oil for her whole life. Motor is only a couple of years old. I am running 91 octane pump gas through her. Not sure what temp thermostat it has. She seems to hold pretty steady around 185-190 degrees though. pretty choppy, low idle. Not sure what other info would be needed in order for some help.

What should I start looking into for this engine knock? First things to check?

THANKS fabo. I know I can always count on good info at this forum. This motor is a beast!