Sm465 vs nv4500 shifting

Box Rocket

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NV4500 will shift better IMO. Rebuilding the Sm465 with new syncros etc will help and be very close in feel. Others have mentioned this already but a lot depends on how you use your 40. If it's mainly a road rig and sees highway regularly, the overdrive of the NV will be a nice feature. If it rarely sees speeds that would allow for the overdrive, then I would opt for the shorter drivetrain with the 465 and have better rear driveshaft angles. I had a SM420 in my 40 that I had completely rebuilt and it was smooth. Easily one of the best mods I did to the truck for offroad and I always drove it to trails so I was fine with it on the freeway too.
 

69LC

 
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So my goal is to build it with the LS for fun power and reliability. I want it overbuilt and to be able to drive from MI to the Rubicon, Fordyce, Moab etc and drive home.

I was going to build the 465 with a custom short planetary doubler to a modded 205 to be as short as possible. I have a tractor pulling custom shaft builder guy close who can make whatever.

The question about the two trannies came up due to the possibility of using an OD instead of 1:1.
 
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I love my 465 Offroad, the low gear is great. It’s cheap, bomber and comes attached to a ton of 350’s. That being said, I lust after an ls. If I took the time to do an ls, I would absolutely find an NV4500. I dont have any trouble on the highway locally (60mph) with a 350/465 combo and 35’s. I do find myself searching for the nonexistent 5th gear from time to time though. OD would be sweet if your really thinking of driving long distances- there are a list of other reasons I wouldn’t drive my 40 across country again.
 

too tall

 
 
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If you are going to use it more on road then off I would say go ahead with the nv4500. IF it is for more hardcore crawling, I would go with a 465. I tried to build a truck that would do both a long time ago and it doesn't work. Overlanding or expedition wheeling is one thing but driving a truck that is setup for hardcore crawling on the highway long distances gets old pretty quick. My nv4500 has 15,000 miles on it from new and works as it should. Not sure how old you are or how hard you wheel but, a cheap tow rig and trailer will afford you a better experience. The first time you roll your rig far from your home will be very expensive to get you back.
 
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I have basically the setup you are going for.

5.3 LS truck motor, NV4500, and an atlas. I run 2100rpm at 65 to 70mph on the freeway and have more than enough crawl ratio offroad because of the atlas. I run 5.13 gears in my 14b and 60 front.

The NV4500 is not a fast shifting trans and there is a pretty big jump between some of the gears, 3-4 is pretty big. But I drive my rig too and from trails, wheel, then drive home. It is definitely a nice trans on the freeway, I return between 12 and 15 mpg on the road typically. But, it is not like a more modern Toyota 5 or 6 speed. But in terms of the big beefy trans to run with big tires and HP it is the a good option for a street/highway driven rig.
 

batcon

 
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My 40 had a sm465 in it when i purchased it. Swapped in a nv4500 and I love it. built my rig to drive on road and off. stretched the wheelbase to accommodate the length. with an orion 4:1 reduction and granny low, i can crawl offroad and cruise home on the freeway with comfort in 5th. Both truck trannies but the 4500 is more refined for sure. if you're going to do it, do it once. drive someones rig if you have access.
 

69LC

 
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Ok, so I will be using an NP205 tcase modded for twin stick and the big input bearing. In anyone's opinion, with the healthy v-8, 6.34 first gear and lousy 1.96 tcase low range, can axle gears get me to a nice sweet spot for a balance of crawling, wheeling and highway driving?

I have time to plan, save and build, so like many of you have said, do it right once.

oh, and to refresh, 37" radials for street and snow, cut chubby 38.5" swampers for the trail...
 

Cruiserdrew

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What about a low range kit in the 205?

Then keep your current gears for the rubber overdrive.

I sort of have this in my 40 but not as heavy duty. SM420/Orion 4:1/ 4.11. Works great with 37s.
 

69LC

 
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I'll have to see if that fits a stock case.

...nope. it doesn't. The Lomax is a whole new tcase to fit the 3:1 gears.
 

too tall

 
 
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If you are going to regear I would go to 4.88's . 4.56's would be a waste of time for the gain. 5.29's have many small teeth and are not as strong as 4.88's. This is in regards to the cruiser front axle you are planning. If you are going to a bigger front axle you could go lower than 4.88 and not have to worry about strength so much. My rig has 3fe,sm420 and 4.88's on 40's and it does everything around here adequately.
 

GLTHFJ60

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Low range kit in the NP205 still only gets you 3:1. An improvement over 2:1, but not by much.

Can you afford (in money and length) a doubler, like an ecobox? I have one in front of my NP205, behind my ecobox, and I LOVE it.
 

69LC

 
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I was going to build my own short planetary doubler between the 465 and 205. The tail housing of the 4500 kinda makes that impossible in a 40, even with moderately lengthened wheelbase. My rear axle is already ~3.5” back with a spring flip, links would let me go further.
 
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