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GQ1 means you have a standard rear end with no traction adder. Look for another rpo code in the glove box for the ratio. It usually starts with GU or GT:
GU2 2:73 ratio

GU4 3: 08 ratio

GU5 3:23 ratio

GU6 3:42 ratio

GT4 3:73 ratio

GT5 4:10 ratio

GQ1 Open Differential Rear Axle

G80 Positraction/Locking Rear Axle
 
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1988 C1500 Silverado, 5.7L with some go fast parts.
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Did the G80 come in multiple axle ratios?
Yep, it came in different size rear ends too like, 10 bolt 8.5/8.6", 14 bolt 9.5" and 10.5", etc.

The 10 bolt G80 "Gov Lock" is also known as the :Gov Bomb" :rolleyes:
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So to put this question to rest. When looking at the build sheet I sent that says - G80 with a GQ1 rear axle "standard", there is no way to tell what yhe axle ratio is without jacking up the rear end, turning the tires and counting the driveline revolutions.
 

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1988 C1500 Silverado, 5.7L with some go fast parts.
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there is no way to tell what yhe axle ratio is without jacking up the rear end, turning the tires and counting the driveline revolutions.
Look at post #2, you ratio should have a GU or GT prefix but, there's no guarantee someone hasn't changed the gears before you bought the truck.
 
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