Buddy of mine has a stick car that we have worked on over the years. Heavy. Makes the car dead hook and go low 9s @ 1.30ish in 60 with his clutch tune up.

Has progressed over the years from 12 bolt, to Dana, to 9", to good 9" with Pro Stock level parts. Just stepped up to a 9 !/2 set up. Gear life improved dramatically.

His contacts at MW and other places confirm - gear quality has declined over the years.