Yep, DO NOT turn the crank if the drive to the cams is disconnected. It will be pistons hitting valves rather than compression that is your problem.
Turn the crank back by about 60 degrees from the TDC marking with the belt off. You should then have all of the pistons well down in the bores so it is then safe to turn each of the cams to the correct position for belt fitting and lock them using the kit.
Having locked the cams, rotate the crank forward by 60 degrees to the TDC position, lock it and fit the belt.
I find on the 3.2/2.6 without the adjusting lower idler, that if you rotate the crank about 1 tooth back before fitting the belt in an anticlockwise direction (i.e. over cams 4 and 3 first, then rotate the crank back to TDC before fitting the sprung tensioner, there is less likelihood that it ends up a tooth out.
You can always transpose the belt markings from the old belt to the new using some tip-ex. While not essential it does help.