I decided this morning that I'm going to give the OEM part a try before I go to a custom shaft. The first CV I broke (which I assumed was an OEM shaft) was in conjunction with a broken tie rod. I'm not positive but I think the tie rod went first, then the wheel cocked off to the side and snapped the CV collar. That would be an understandable failure condition, whereas the last two failures (NAPA parts) were 'normal' abuse failures.