I posted this yesterday but it appears to have disappeared, so here goes again.
Remove No. 1 spark plug and turn motor over either by hand or with a socket & bar in clockwise direction, place a small screw driver or piece of wire in plug hole and when it is at its highest that is TDC, may be better if a second person helps, this will get you close. It doesn't matter whether it is compression or exhausting stroke, then mark a line opposite the heavy or "0", this should be TDC. Replace spark plug and start motor, the harmonic balancer mark should be visible so you can then adjust to min. 10* BTDC, this will mean that the harmonic balancer mark moves backwards towards the left. If you get hold of tape that goes on the harmonic balancer and is placed to the right of the mark.
As Chryco said there is 2 different covers that means 2 different balancers, you might have a miss match between the 2 or the outer ring on the harmonic balancer has slipped.
There is a positive way of making exactly sure of getting TDC but is a bit more involved, the above is close, email me if you want any more details.