My truck has a stock 727 with 350,000 miles on it. For the kind of work I want to do with it, I figured I'd at least need a torque converter and shift kit, and that's getting to be about $1000 right there...

So I basically -need- to do a manual conversion. NV5600 is out of the question, NV4500 is still pretty out of the question since they seem to go for $1500 for just the transmission, nevermind the clutch, pedals, bellhousing, etc. Getrags are about $500 cheaper, for the same situation, but they seem to be RARE.

One thing I want to do eventually is get a US Gear aux trans for the truck, which would take care of overdrive anyway, in addition to working as a gear splitter (they're roughly $2000, maybe $2500). It'd basically allow me to pull more weight, more efficiently, with less power in the engine (and therefore less fuel cost). So really, I wouldn't need a 5-speed OD transmission.

I looked into the NP435, which is the kind of trans that was optional on my old truck. Apparently they put them in EVERYTHING from the 60's into the 80's, except for Dodge, which is listed as using them until 1990 everywhere I've looked. The big three all used them in medium-duty trucks as well up until the 80's, but Dodge wasn't making medium-duty past '78. Did they come stock on some CTD Dodges?

 

Nope The NP435 never came behind the cummins
I dont think one would hold the torque of the cummins

 

You can put a T-19, SM-465 or an NP-435 behind a Cummins using Cummins 4BT step van components but the clutch would be under size. I fail to understand your financial logic. If I had to initially choose between spending $2500 on a US Gear auxiliary unit or a NV-4500 conversion I would pick the NV-4500 with out any questions.

 

I see getrags all the time on here, 1stgen.org, craigslist.org, and a few other places. Have you looked there?

 

Go for the NV 5600 now and forget about the add-on overdrive. I haven't heard too many people say they could use more than 6 gears unless they wanted some thing lower than 1st.

Jed

 

The 5600 has been discontinued by NVG. They're tough to get a hold of, it's hard to find parts and, when you do, they're big bucks. They're also not at all easy to work on for the diy-er.

The real advantage of a GV unit (aside from splitting the 2-3 shift on the 'rag) is the ability to pull at highway speed in direct. 4th-over (GV) is identical to 5th in terms of ratio, but 4th takes all the load off the countershaft and greatly reduces heat when pulling heavy. My 'rag will hit 260 easily when pulling 8-10k in 5th It'll drop 50 degrees in under a half hour pulling the same speed in 4th...

 

The chevy sm-465 from the 70's and mid 80's is nearly bulletproof but the 1st gear is so low it useless even in a gasser.Chevy made the sm-465 with a overdrive but only as a standard trans in a half ton 6.2 diesel chevy (harder to find than a getrag). id keep lookin for a get a rag.

 

it is troubling about the ratio issues we have on here
Towing in direct vs OD is optimal, however our rear ends are geared too low to make that feasible. Enter the 3.07 axle that is made out of unobtainium and has its own set of issues...

 

Yeah, I wasn't seriously looking at the 4 speeds for use behind the CTD. I could actually use the granny gear but wondered if the shift from first to second would even be possible behind a diesel. Plus even though they used them in dump trucks and the like, they probably made a lot less than 400 ft/lbs of torque on the input side.

The reason I want an aux trans at some point in the future is to make better use of a smaller amount of power... but that's at some point in the future. I did look at some Eaton and other HD transmissions, and they seemed to be fairly reasonably priced and available in any kind of gearing you'd want, but I just assumed they'd be far too big to fit in the truck without hacking out the entire floor and lifting the suspension or something. Not true?

 

True, unfortunately There is the Allison option....

 

you'd have to to a body lift something fierce to fit a roadranger under there... 13 sp anyone??

 

The sm 465 was made from 68-91 or 2
I wouldn't say 1st is useless. I use 1st in all my old chevys they have the sm 420 which has a lower 1st gear
The 465 was never offered with an overdrive

 

I don't suppose you know what its power ratings are, do you?

Although I did look up the power ratings on the NV5600 and they're basically right at the numbers that a 3rd gen CTD would put out, so they're probably conservative.