what should I do?

[pathaymond]

I helped a new found friend do the jig fix this week he has a 97 3500 5 speed with 410 rear. I have the 98 3500 auto with 354 rear. I pull often and have considered that 410 would be better for me. he never pulls and would like the 354 rear. we have made a decision to swap since mine has 70K his has 80 k and both have been taken care of. Is there any reason either one of us should not do this swap. I would not want to hurt him or me in the process and what can I expect and he expect in return for the swap. I do travel alot of miles with no pulling. but where I pull is not flat!! I like the ability to lay into to the loud pedal and let her roll. I know I will compromise that ability maybe thats a good thing!! any input from anyone would be appreciated by both of us Thanks in advance Patrick

 

[BCFAST]

Dont do it!! You have the proper gearing to get mileage, run a decent speed AND pull... . you just need more power and you wont notice ANY problems driving or pulling! IMHO, the 4:10 is for folks who are either: 1. still thinking like a gasser owner, or 2. Pulling loads well beyond the capability or the chassis (not the motor!) My vote is for you to throw a little money at BOMBing and enjoy what youve got! Let your buddy suffer with bad mileage & a roaring engine (or write a check).

 

[JJW_ND]

3.54 best for 12V trucks

I concur to leave the 3. 54. Even the mildest power upgrade will make your pulling problems go away.



The over thing to do without uping the power that will really help a 12V 5sp is the 3,000 Govenor spring kit from Piers.



I too wanted more gears with a stock engine. Hotshotted pulling new stock, horse and flatbed trailers. I had the power turned up without adding any parts (pretty mild... . +-250hp) and I never found myself shifting out of 5th again.



I have pulled with guys running 4:10's and the noise is quite noticable running the higher RPMs.



jjw

ND

 

[tschwab]

BOMB your motor, then go see Bill at DTT to BOMB your transmission, you won't belive the difference! I concur, the 3. 54 is the best bet with the mighty 12V unless you are using it for a specific application as mentioned above. This has been noted numerous times here on the boards and in past issues of the TDR magazine.

 

[pathaymond]

I want to thank everyone for there input so far. I have had many tell me bills tran rocks I want one now. My friend turbo told me of a truck he has been in with bills valve body etc. turbo is good at making you feel like your there and man I liked the feeling. . this slush box auto is a lame excuse for a trannie behind such brute force as the ctd. one step at A time i guess my gauges should be here anyday then I have something to work from right. thanks alot again Patrick

 

[Hummin Cummins]

I cant give an opinion either way, but just remember if 4x4's you gotta swap the fronts too!!!

 

[Dennis Garrett]

Out on the highway, there's a 200 rpm difference between the two. I always figured the only reason to gear down to 4:10's was if you didn't have the power to use 3:54's. Shouldn't be a problem with the Cummins... ..... There's Towin' & then there's Towin' & Goin' !

 

[Extreme1]

I'll take the other side...

The automatic has a taller (numerically lower) OD ratio than the 5 speed. You CAN just add power (and you will like it!) but both trucks would be better with the swap, especially if you will spend some time to complete your power increases.



200 RPM isn't much, if you spend all your time on the interstate, keep your 3. 54's, if you want to pull hills on secondary roads better, swap in the 4. 11's.

 

[Dkevdog]

I've never pulled with a 3:54 but I agree that if you pull often or at or near gross, the 4:10 is the way to go. Yeah I'm at 2000 doing 65mph but that's the way it goes.



Kev

 

[SOOT]

Having 2, 1 with the 3. 54 and 1 with the 4. 10 I have been able to compare them with the same trailer loaded the same way. If you do lots of heavy pullin in the hills and mountains the 4. 10's are the way to go, but on the other hand if you do mostly light or empty driving or flat lands the 3. 54's are the way to go. The 3. 54's give much better fuel milage than the 4. 10's but cut down the power to the ground.