Looking for someone to chat with. My 3.55's are killing me when towing my 4,000# trailer. Looked at all the RPM charts and don't think 4.11's will give me as big a bump as the 4.56's. Concerned that I may not be able to reach highway speeds of 70-75 MPH. Thanks.

Mike

 

4.10's will be good, especially if you run 33's....you wouldnt want 4.56's with 33's IMO


have you done the Plenum? if not theres your problem.

 

I don't know if you've tried the forum search feature here, but there have been some threads on this in the past.
One of our mods...SilverDodge might be able to help you as well. I think he ran 4:56s with 33s for a bit. Shoot him a PM.

 

Try using the chart on this link: http://www.accuautoparts.com/#
Look to the right and click on the tab: "Gear Ratio Calculator"
I used this to make the decision on my gears for my 37" (+/-) tires.

 

I run 4.56 with 285/75/16, which is roughly a 33" tire, if I am correct, and my truck has plenty of power, and no problem reaching 75 mph and cruising comfortably.

 

Perfect! Thanks for your post. I run the same tires. So your speed at 70 is about 2,200 RPM or so, what is your gas milage like HW/City?

Do you ever feel like you should have 4.10's and not the 4.56's? Thanks again.

Mike

 

 

^^^open the hood and look up there will be a tag


3.92gear with 245/75/16 at 67mph tachs 2,000rpms

 

Keep in mind that's going to be with OD on... to tow you want OD off, and your RPMs will be higher.

Cartman

 

I get around 14, that's in a mix of city, highway, and rush hour traffic. I thought long and hard between 4.10 and 4.56 before I had this swap done, and I am really happy I went with 4.56, 4.10's wouldn't have made nearly the same difference, IMO.