If you have the factory cams there is not much room for adjustment, as they only provide approximately 4deg of overlap, adding more overlap will provide better high end power in theory, as long as the cams have enough duration. If your cylinder head has not been machined, or has only been machined lightly once to ensure a perfect surface for a re-build you will not have any problems. As the FS-DE is a non-interference motor it is possible to adjust the timing of the cam gears to whatever you'd like without an issue. Once the cylinder head is machined too many times it could create an interference situation, at this point you would need to buy a "test spring" this is a valve spring you can install and then push down with your fingers in order to measure valve to piston clearance with a dial gauge.
