"Dell-adapted Micro ATX - the wiring for the front panel and the back panel connectors are nonstandard.
If you use a non-Dell board you're in for rewiring, sheet metal modification, and remember - the copy of Windows is tied to the Dell BIOS and won't activate on a third-party board, so budget for a new, retail copy of Windows if you're rebuilding on a non-Dell board."
disregard the lower end, as your not trying to replace anything but the case
But in short, you should be fine, just take the golden placements underneath the mobo and put them in the appropriate spots in the 902.
A bit off topic but you will want to get rid of the green thing used to funnel the hot air out, as you wont need it anymore, get a couple air cans and clean out the heatsink, and then ziptie a fan somewhere near on top of it to make sure your actively cooled
I dont think getting aftermarket parts for the pentium will be beneficial, as its vastly outdated, but a case is a sensible upgrade as you can change out anything thats inside
The antec 902 is a nice case, I enjoyed my time with it