As you guys now I have a T56 in my trucks. My 06 aka Big Red has 373 gears with 275x55x17. Well after putting about 200 miles on it this weekend it does not like 6th gear unless I am rolling and even the I can not maintain the speed. I know the truck is heavy but I do not want a gear that will make First useless. The 410 gear is out because that will not make a big difference for the money. So with that do you think a 433 with this tire size will ultimately give me a 410 ratio?

Also Mr. Gibbs has 373 gears with a 275x45x20 do you think a 433 or 410 would be best in that truck?

I know the TA and the Camaro came with a 342 gear and 26' tires and I am trying to get the ratio close to the 26' tire with 373 gears.

Thanks for your help.

 

I would go with 4.30s

 

I have 275/55-20's and the 4.30's is the highest I would consider. I could have gone with 4.56's and been just fine.

 

But what ratio do you think that is with the 430 gear? Is first gear still usefull?

 

I dunno, you'd have to do the math on the tire diameter differences. There are ratio/tire calculators all over the internet to help you out. 1st gear is very useful and would be with a 4.56. Heck, the stock 5 speed that was in mine had a 3.82 1st gear with 3.73's. that is a 14.24 final ratio and the 4.30's and 2.62 1st is 11.26:1

 

How is it in 6th gear on the highway?

 

The 4.30's at 80mph it's about 1800rpm. It is ok for my 370 with good torque but I wouldn't try it with a 4.8.

 

Damn even with 430 gears your tacking that low of an RPM

So with my 17' tires I should be arond 2500 huh?

 

Go ahead and do the 4.56's, I love mine with the 6 speed and you can use 1st just not a wide open throttle.I can barelly use 6th now because it bucks and surges at low rpm. Man I need a tune.

 

What are your turning in the RPM range with that kind of gearing?

That just seems to be soooo much gear for the street? My Gibbs truck would just spin on the street with those gears?