Try to make one block by reducing by 1/3. 6" would be 4". 3' would be 2. you will still need your seem allowance. Just try a sample block and see if that works. Also you could make the spacers 4"x8". Some one else may have better ideas but that's all I've got. Sorry. I have no problem to stand and be corrected, gently please. I have just either eliminated or added blocks. Really like that pattern!