Chevrolet: cam timing, ls1 corvette, timing gears

Question
I just replaced a cam on an LS1 Corvette.
Someone had already replaced the timing gears and chain.
I used a degree wheel to find crank top dead center and made my own mark on the sprocket.When I line up the marks cam at 6 o'clock and crank at 12 o'clock the intake and exhaust are still slightly open , When I rotate the engine over so both marks are at 12 o'clock the valves are closed as if in the number 1 firing position.
Is this correct ?
Thank youfor the help

Answer
I usually remove the sparkplug at the #1 cylinder so you can tell if the pistyon is at the top. Otherwise you could still be off by 360 degrees. Otherwise #6 might be at TDC instead of #1.

I insert a plastic straw through the plug hole and that way you can feel if the piston is at the top or or not.

Obviously don't leave the straw in while you rotate the crank.