quiltingnonie

I would like to enlarge a block because the pattern calls for
256 blocks. (too many!) The focal print in the block is 3 1/2" square, but I would like to make it 4 1/2" square. I'm not confident on figuring out the larger measurements for the bottom and side piece. Also, there is a 1 1/2" sashing strip for both the top and bottom of each row, and it is an integral part of the finished design, so am wondering if I need to enlarge it also
:?:
There are so many experts on this board, I'd like to learn from all of your knowledge. :idea: Hope my rough sketch comes thru.
Thanks sew much :D