Ford 4.20 Rear Gear Ratio?

[dartman]

Originally Posted by Dock Dog

I just got a ford rear center section that has a stock 4.20 gear in it. It has 42-10 and a ford emblem stamped on the ring gear. I also counted the ring and pinion gears and they both were 42 and 10. I have never seen this ratio used or heard of this ratio also. Is their anyone that can help me with what and when this was used. Thank you for the help.

Google it "early bronco with a six cylinder. Don't know anything else, but I figured I'd let you know"