Note how the 1330 joint has the same-width cross as the 1350 but caps the same size as the 1310. A wider body will accommodate greater angularity, while a larger cap will be stronger. Greasable or ...

The numbers identify basic dimensions without regard to bearing cap size, which depends on driveshaft and yoke size. For six-cylinder applications, expect to see a Spicer 1100 or 1260.