One thing to be careful of is when looking for a cover with no timing marks and then planning on using a timing tab is to not get one for a 318 poly motor.

The poly has an extra bolt in it that does not exist in any the the 273-318-340 blocks.

We've all seen that stupid section of gasket sticking out of the timing cover a little more than halfway up the drivers side. That hole is for a poly only cover...