You not gonna get much out of that case unless you "punch out" the back where the i/o shield. what do i mean?
Take a look where the ports are, this is the optiplex 740 motherboard, the place where the ports are located is very unorthodox, usually motherboards look like this
notice how if you line them up they dont match? Well that your first problem, if you dont want to "punch out" the back, you may be stuck looking for a similar 740 style motherboard or using the AM1 motherboards but with out any pci-e cards. If you do "punch out" then that gives you more opportunities to use other motherboards. So, "where do I 'punch out' the case?" well here.
The place highlighted in red, take a look on how the case is made, you may have to do more work then usual because of this unorthodox case/motherboard. you may have to flip the motherboard base to the otherside.
well thats it for me. hope this helps