I have a v10 with 4.30 gears and 245/75/16E tires. I am thinking about putting 265/75/16E tires on it and they are one inch bigger in total diameter, half and inch height rise for the rear of the vehicle. What would the total change in gearing be doing that. Would it be close to 4.10

 

This is handy, tells you most of the data https://tiresize.com/calculator/

 

Back of envelope calculation comes out to 4.15:1, so the answer to your question is yes, close to 4.10.

 

Thanks guys you really helped me, appreciated

 

Did Ford ever use that size on a truck? Vans I'm sure.

 

My 2000 f250 with the off road package came with 265/75 16's. Not sure what years or other packages came with it though.

 

265/75R16 was the factory tire size for all of the Excursions.