Sometimes guys get in trouble because the damper doesn't match the timing tab. Here
is a short page describing the differences in the three types most commonly seen and how to go about remarking the damper if need be. Cost is zero, but it won't trick anyone into believing you have a Fluidampr...
It's worth mentioning that using a cover still doesn't guarantee the timing marks are accurate- even if the parts all match. Manufacturing difference and tolerance creep can still make the marks off, so the best bet is to go ahead and do the drill to determine true TDC. DV gave a link earlier for determining TDC, here
it is again.
The bolt holes in the cover can be carefully elongated in order to index it correctly if you find it's off.