I agree with PaperPrincess, there is no way the block can be made from just those 8 squares. We need to see a picture of the block.
Edited: You posted your last description just as I was posting. The block you're trying to make is here -
http://www.ideas-for-quilting.com/si...uiltblock.html
This block divides nicely into 5 equal size segments, so 10" is a natural with 2" segments (finished size) but if you try to do it with 12", each segment size would be 12/5=2.4", which is 2.9" with the seam allowance, very hard to measure accurately. You could change the proportions of the block so that the outside pieces are 2.5", and reduce the center so it's 2", and that would probably still look good, but it wouldn't be quite the same.