RE: Help 99 2.5 V6 camshaft timing marks.
You seem to have found top dead center for cylinder #1. Are you sure you found it on the compression stroke?
Because therocker armsare contacting the cams, it's possible to have a little load tending to rotate the camshafts. For the same reason, the camshaft will not spin a full turn by itself.
Beforeyou rotate the camshaft to get it back into position, rotate the crank backward a little bit to get it off TDC so there's no chance of hitting a piston with a valve. That is covered in the Haynes manual.