3. We retained the 1410 drive flanges at each of the 2 1/2-ton differentials with Tom Wood's driveshafts. Our obvious weak points are the factory 1310 front transfer case CV and 32-spline slip yoke in the rear. So why keep the NP242D case if it's the weak link? The simple answer is cost and time. Retaining as much of the factory drivetrain as possible keeps the overall cost and build time down, which equates to less money spent and more time on the trail.