There SHOULD have been bolts through the dowels. Doesn't matter if you, or whatever catalog you are looking at says so or not. If you look in the holes on the block they are threaded, and should have had bolts that were about 1/2 an inch longer than the other 4 in the block, similar length to the two in the pan.
If you are sure that all 8 holes are empty get a pry bar in between the block and bell and start working it. It is not uncommon for the torque converter to get stuck and make it hard to seperate the two assemblies, or the dowels to get corroded into place. If all else fails get the drive shafts out, trans cross member out, and get aggressive with trying to tear that trans off the block.