Didn't bust up your valves?
lucky sob, invest in the lotto now.
1st, you need a new sproket and chain, of course you know that. pull the head cover off. While you're at it, replace the head plug.
2. Put crank and TDC. Guess what? w/o a cam attached there's only one.
3. Look at the cam, on the shaft there are 2 marks down the middle. Those are supposed to be level with the head. Also, the pin that connects the sprocket to the cam is supposed to be at 1 o'clock.
4. check operation, check tdc, check cam aligned, then repeat. And repeat again. You don't want to have to take the head cover off again do you?