D60's are good but many different versions to sift through. 14 bolts are rock anchors without shaving housing and ring gear. 60/14b has best aftermarket support, but for initial cost a Ford superduty set, HP60/Sterling, is better. Catch here is you'd need to swap axle tubes to make passenger drop, but that's only about double the work as shaving a 14b but with way more benefit. You'd better link at least one end during this swap or I'll smack the s*** outta you.