4kq timing mark help needed

[CTDiesel at aol.com]

For the 4kq, the Bentley book says to line up the camshaft mark (dot) with
the top of the valve cover gasket/ head and then the crank flywheel to the
"0" mark.  That seems to leave a lot a room for error being that the cam mark
lining up with the top of the v.c gasket/ head is left up to the discretion
of the mechanic.  I've noticed the cam can be off one tooth and still be
lined up with the v.c. gasket/ head. and the flywheel be off mark.

Does anyone have a full proof way to line up the marks or any other
suggestions for timing that vehicle?

It seems everytime i put on a new rubber valve cover gasket i always get a
leak on the injector side.  The top of the head is perfect level and the
valve cover is not bent either.  Any ideas on how to elimate that next time

DJ