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What kind of gear ratio came on 70 383 Road Runners with non sure grip rears?



Only 1 gear ratio 3.23 , any other gear ratio available in a 1970 RR wit ha 383 and auto trans would have been with a suregrip .

As far as swapping gears to your suregrip chuck , as long as it's the same case numbers. Gars do not swap between the different carriers BUT you can put that suregrip in your open chuck as long as you use the correct bearings for the sure grip being used , cone and clutch used a different bearing , the bore in the chuck is the same but the carrier is different and requires it's own bearing and race.



Thanks to all for your replies. Both carriers read 489. The 3:23 sure grip ring and pinion are worn and was advised not to use them for I might get a humming sound from it.
So I would like to use that carrier with the sure grip internals for the 3:23 open gears that are in the car now.



You can do that , just go thru the suregrip in the one with worn out gears , it's a cone type , they are JUNK by design , if the gears are worn the cone type is probably on it's last leg also .