im having a brain fard at the moment, cross flow tappets, how do i know for definate when a valve is fully open or closed without just looking?

Turn it via the crank pulley untill inlet No1 fully open, set inlet No4, Ex No1 fully open set ExNo4 and so on. Don't see how else you'd do it with out looking unless you want to do it by feel in the dark... or why you'd want to do it with your eyes closed...

Google "rule of nine", I'd link, but it's a pain when I'm on my phone

i mean, is it only by looking at the valve and rocker arm until it stops going fully up that you can tell?

You can do it visually by marking the crank pulley when the valve just stops opening and again as it starts to close.Set the crank pulley in the middle and adjust appropriate valve.If you have a dti then even greater accuracy can be achieved.

Rule of nine works fine. IIRC number the tappets from 1 to 8 front of block to rear or vice versa then turn crank till you see one fully compressed then alter/adjust 8 8+1 =9
then turn till 2 is fully compressed and alter 7 7+2=9

etc etc.

ok job done all se, thanks guys.