The 240 hubs are scalloped, so there is no way that would work. The 280 hubs are round, but they're actually thicker where the studs come through, and machined flat on the back side. I'm sure theres a way to do it, but safely? No. Just get yourself some Z31 front hubs if you want 5 lug.
EDIT:
This should be in the brakes, wheels, tires, suspension forum btw.