sunrise you can use your 2 1/2" blocks. For the HST you would use 2 7/8" or 3" if you want to square them up. Depends how accurate your 1/4" is to make sure they finish at 2 1/2" Your units would end up 12 1/2" x 6 1/2". That should match your center is you used 2 1/2" squares
Last edited by jaba; 03-31-2015 at 07:20 AM.