33's in place of 31's?

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78C10BigTen

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Would anyone know if i could fit 33x12.50x15's on the rear of a stock 78 c10 big ten? It has 31x10.50x15 on it now but not much luck finding any used. Just curious if theyd fit up under the stock back end. I personally think they would as it sits pretty high out back. Thanks for input
 

shiftpro

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They will fit... but I would be concerned about your rolling gear ratio. These tires will effectively raise your gear ratio. What rpm does is sit at on the highway?
 

78C10BigTen

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Round about 2700 at about 75-80. Its a 3.08 rear
 

bucket

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Bolt 'em on and show us pictarz!
 

bucket

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Also, I ran my K5 with 33's and 3.08 gears for a while. It was a little sluggish off the line, but overall it was a decent combo for DD duty.
 

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Also, I ran my K5 with 33's and 3.08 gears for a while. It was a little sluggish off the line, but overall it was a decent combo for DD duty.
No doubt, but your K5 is 4x4 so extra weight and gears and all... on a 2x we can generally get away with slightly higher gear ratios.
 

bucket

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No doubt, but your K5 is 4x4 so extra weight and gears and all... on a 2x we can generally get away with slightly higher gear ratios.

Yep, that's what I meant. Should be ok on a 2wd truck.
 

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