In 1.4, it's hard NOT to find 2 next to each other. It makes it so that there's 3 different Z coords, but if you travel staying on the Z coord you'll find tons of fortresses. Also, if you've got a macerator and a minium stone, you'd need only 1 blaze rod or 2 blaze powder to get infinite amounts. A macerator gives you 5 blaze powder from a rod, while a minium stone will make a blaze rod with 2 powders.