Great CAD work it looks really similar to our gen 8 reference CAD design that we release every year. Take a look:
http://uncert.mines.edu/research/csr/FIRST/Gen8.htm
If I may, I would look at some stamped pillow blocks like the AMI Bearings BPP1-8 rather than try to modify some of the 8020 parts for your bearing blocks. Here is a link to there catalog page 15
http://amibearings.com/pdfs/mounted_normal.pdf