A compression and leakdown test will give you about a 90% guarantee that everything's fine. You can still have some damage that isn't readily noticable, but may pop up later, so if everything checks out, just keep an eye on fluids, fuel mileage and normal driving behavior. I would definately have those two tests done, as well as re-tensioning the timing belt at a minimum. When you have the valves adjusted, check for signs of water vapor in the head, which will look like somebody exploded a vanilla pudding cup under the valve cover, in which case that will have to be cleaned and the oil changed immediately. While you're taking this new-found interest in your engine's well-being, check the radiator level every day first time you drive it, and look for oil in the coolant, or unusally low levels.

BTW, yes I'm a mechanic, I restore British sports cars when I'm not at school training for a cleaner job, I've raced in many levels of motorsports for 11 years, and try to learn from everyone elses mistakes because it's cheaper that way