Like I mentioned previously, you need to check the cam timing first to even know where it stands to begin with. With all the machining tolerances in the timing set the keyway locations in both the cam and crank, it is doubtful that with the dots lined up on the gears that you are exactly at either 0 advance or retard with the cam spec sheet, if you have one. Its kinda' like just sticking your distributor in the engine, and turning it clockwise or counter clockwise until the engine starts. But until you put a timing light on it, you dont know if you need to advance or retard the timing. Also, you will need to check your P/V clearance as well to establish if you have or dont have adequate room to make changes in your cam timing to begin with. Advancing the cam makes you lose intake valve clearance, and retarding it makes you lose exhaust clearance. If the head is installed and torqued on the engine, you will need a dial indicator to check your P/V, if its not installed yet, you can use the clay method to help determine it, if your not that familiar with the process. Also, most people assume that TDC is the point at which the valves are closest to the pistons, and it is not, thats why a degree wheel is almost a necessity to do this correctly....
