[woode]

Option 1:
Pull the motor, pull the heads, inspect everything.

Option 2:
Do nothing.

Not sure what you are looking for us to tell you? Whether the car seems fine or is acting up, the above are pretty much your only two options regardless. If it hit 8500rpm under minimal load, I wouldn't be too concerned about it personally. Only you know things like if you let the clutch all the way out, how fast you were actually going, etc.