Well, I'm almost ready to take the leap into CTD ownership -- planning to order a 2500 SLT 4X4 SWB 5spd on Friday. ;D I live in the Peoples Republic of California, so I'm only allowed to have the REDUCED OUTPUT Standard Output CTD (235 HP). :'(<br><br>I just have a couple questions that I'm sure someone here has the answers to (or at least some good opinions!!).<br><br>First, should I get the 3.73 or the 4.10? I'm planning to put on the BFG 315 70R17s. Assuming that the stock tires (265 70R17) and these BFGs have diameters reasonably close to what I get by simply calculating the diameter from the numbers, the stock tires are 31.606 in. and the BFGs are 34.362 in. Assuming my calculations are correct, this reduces the rear axle ratios to:<br><br>3.73 -&gt; 3.43<br>4.10 -&gt; 3.77<br><br>I'll be pulling a 5000# trailer around the Colorado Rockies this summer. With the SO will I have any problems maintaining 70 MPH in 5th gear on the high passes in Colorado if I go with the 3.73?<br><br><br>Second, I'd like some input/advice from you folks that live at the higher elevations on the performance of the CTD. I'll be retiring from the Navy in a couple of years and planning to move back to Colorado. In addition to pulling a camper, this truck is going to have to get me into hunting camp and my favorite alpine fishing spots. What are some of the important considerations for driving diesels in the rarified air of the Rockies? How soon should I worry about getting gauges, better air intake (like the Scotty), more power (such as an Edge box), etc? I don't expect to pull much more than 5000# for a few years at least.<br><br>Thanks in advance for all the advice. I've been reading the forums on this site for about 4 months -- lots of great advice and its really helped me make up my mind to go with the Dodge instead of the Ford.<br><br>F11Engineer

 

I have seen numerous posts where people are very unhappy with the SO equippped with the 3:73 gearing. Since you say you will be towing in the Rockies I think the 4:10 ratio would be the way to go. Just my opinion.

 

I think you'll see an almost unanimous vote for the 4.10 gears especially if you are going to run the big tires.

 

I would agree with the crowd. 4.10 gears.

 

With only a 5000# load and the 5 speed, I think you'll be allright with the 3.73's - even with the larger tires. I'll probably be the only one to endorse the 3.73's..but it is my opinion.

 

Did you make the fatal mistake of becoming a CA resident when you transferred there? Since you're in the Navy, if you kept your CO residence - or anywhere else, you can register a vehicle there completely legally. Which means you can go to NV or wherever and get the HO, register it in your home state and bring it back to CA. Why not do it that way?

 

4.10's enough said.