Im going to either 4.10's or 4.56's when i save up the money lol

 

I also have drove the 09 Ram with the 3.21 and the 3.92 and 20" wheels. I absolutely agree with you, there is a noticeable difference. The 3.92's are much faster out of the hole and they give a much crisper engine response all the way around.

 

Thats even better. Only down side for us 4x4 guys is we have to pay double for gear changes.

 

YEP, and thats why its going to have to wait lol

i got quoted (4 wheel parts) 1500-1600 for either 4.10's or 4.56's with a auborn LSD and the install.

 

just go with the 4.56's because there's a high chance you'll regret not getting them when you get the 4.10's... with the 4.56's you cant go any higher on our axles without alot more money and work. They cost the same so as i said in your exhaust thread, go all out!

 

Thats what im thinking, its just i would like to know what kind of power im going to have in top end and what kind of MPG ill be getting at 70-80 MPH

 

This is exactly why gear ratio was one of the top things I looked at on this truck. Window sticker as well as the axle tag in front of right rear wheel on rear housing. On my 06 FX4 I had done gears with Yukon 4.56 and between the rebuild kit, gears and install, it cost me $2200.00. I had a custom dyno tune on the truck so I could recalibrate the speedo and had the top end limiter removed but with 4.56's and 34" tires, top end was 101 mph. ( before the regear, in drive, could easily peg the speedo in 3rd gear, then it would shift into 4th/OD at 121 with the stock 3.73's. ) My advise, I wouldn't do 4.56's again, I do too much highway driving now, unless you are going with 35"+ tires, 4.10 is enough gear here.

 

If you guys with 3.21 and 3.55 want to change gearing, I would not change to a 3.92. If you are going to spend the money, go to the 4.10 to get the best improvement.

 

You can go as tall as you want with respect to 4.10s or 4.56s but be sure to think about your warranty. There's only one trim level with the 4.10s from the factory so if you put anything over 3.92s on your truck, just be sure you're willing to overlook the potential warranty issues if anything goes wrong. Not trying to rain on anyone's parade but just something to consider.

Jason

 

Would someone please take pity on engine-ignorant dullards like me and explain something?

What do you guys mean by "3.21" and these other similar numbers? It doesn't correspond the gear ratios since the 5-45RFE first gear is 1:3.00, right?

(BTW, the link below (from 2003) has a good description of the history and gearing from sgbofav.) :

https://dodgeforum.com/forum/dodge-r...e-5-45rfe.html

Thanks a bunch!