Keep the housing, buy 31 spline axles, Moser makes 31 splines that use the same size bearing (inner diameter and outer diameter). I would look at buying a center section already built rather than putting one together yourself and paying someone to set up the gears. I bought a strange nodular case 9 inch housing with daytona pinion support, 1350 spicer pinion yoke, 31 spline locker and 3.75 richmond gear for under $700 and it was barely used. It's overkill but still cheaper than piecing one together.