If the valves on the head for pistons 1 & 4 are fully open does that mean that the piston is on it's way up, or on it's way down?

Also the other night my friend swapped out my stock cam gear for a skunk2 cam gear on my d16z6 motor . . . . but I am not sure if he made sure to put the skunk2 cam gear at tdc the way that the stock one was, so can someone tell me where the TDC mark is on the skunk2 cam gears?

Please post up asap . . . we are now gathering the tools to work on my car so the sooner the responce the sooner we get started

Thanks guys!

Ohh yeah . . . does it make a difference if we use gasket sealer on the headgasket or not?