# '67 GTO rear end gear ratio change



## 67gtoconv (Jan 8, 2014)

I now have a 4.3 rear end and want to go with something with better gas mileage. Does anyone know which is the highest(lowest?) ratio that will fit in this 10 bolt, looking to get in the 3.2 or 3.5 range. I heard there are different sizes of differentials that will only let you go to certain ratios. This is a posi unit, I hope I can keep the posi with the new ratio.
Thanks


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## 05GTO (Oct 6, 2004)

The best BOP highway gear for your carrier is a 3.36 or a 3.55,


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## geeteeohguy (Feb 2, 2008)

X2. I would recommend the 3.36, but it's harder to find. 70 mph cruise vs 60 mph of the 3.55. Save the 4.33 gears....they are rare and sought after.


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