Which timing cover??

For 70 and up small blocks the timing marks should be on the drivers side. And as mentioned in another post make sure your balancer has the mark to line up with the drivers side. If the balancer is the wrong one, you can always re-mark it with a paint stripe to line up.

As for your current cover not having the timing marks cast in, that leads me to believe it is a 68 or older cover. In 68 some of the small blocks used a timing tab that was bolted to the two bottom water pump bolts. I think sometime in 68 they started to use the passenger side cast in marks.