It's likely to have low clearance factor as the bottom of the box passes top of springs in installation due to the way the valves are angled, but as long as there's clearance installed should be fine, and so long as you have the correct spring collars? I believe the rockets genuine box have the casting relieved where necessary in those areas(citation)? I had a casting dag in the inlet side that I carved off to be sure. Is that what you mean?