Yeah that's what I plan on doing. I was talking more along the lines of the front axle if I were to swap them both out for ones with 4.10s. But since you fellas are saying it really isn't necessary with the 4500, I'll skip it and just do some preventive maintenance on my current one.

 

100% 4.10s and an NV4500 is overkill unless your running 40s or bigger tires. I've been considering swapping to 3.73s or higher in my RCSB on 33s possibly 35s soon when I do an axle build just so I don't have to shift so often.

Front diff give it a line change and run it! If it does fail which seems to be very very rare. Usually axle shafts break first. Just buy a junk yard pull out for a few hundred bucks.

 

One last thing, swapping the rear, did you guys have to modify the driveshaft any? Like different U-joint or shortening of the shaft? What about the 4500, is it a direct swap, xfer case from 3500 bolts right up? Just need to flip x-member around? No DS mods there either?

 

The OEM drive shaft should have a rear joint size of GM 3R. No length change should be required. You have a couple choices on what to do about the U joint issue.

1)You can get a conversion joint that is 3R on one end and 1350 on the axle side.
-The down side is the conversion joint all seem to be greasable which are weak and tend to break. (I just killed one last week)

2)You can remove the 3R yoke from the 10bolt and bolt it directly to the 9.5sf thus giving you a 3R joint on both sides.
-This is the cheapest option but you have to be careful when removing and reinstalling the yoke there is a certain way to do it.

3)Get a new shaft in yoked to 1350 and run a regular 1350 U joint
-Cheaper of the strong options available

4)New driveshaft Yoked to 1410 and a new yoke for the axle that accepts 1410 as well.
-Most expensive option but not having U joint blow apart is kinda nice. (this is what I just did this week)


On a 4x4 truck the NV4500 swap should be very straight forward, you need a different reverse switch out of a GMT800 2500 truck that came factory with an nv4500 I dont have a part number sorry.
Cross member should fit fine but depending on the exhaust setup the Y pipe might need some minor modifications. X case bolts up as long as its a 32 spline model and you will need a new transmission shifter to go with the NV4500.

 

Any recommendations on one that's similar in length/style as the 3500? I like the positioning of it. I greatly appreciate all the help and can't wait to get this fixed asap! Found one for 770 with 86k miles. Figured I'd stick an Auburn or Eaton LSD in it before installing it.

 

Same position shifter you mean? I've had a couple different ones.

1)The stock 2005 GM2500 Nv4500 shifter is as close to the NV3500 shifter as you can get. Infact you use the same stick it's just the shifter assembly you swap.

2)I've also used one out of an earlier 90s truck and disliked nearly everything about it. Very loose shift gates, wobbly in neutral, and the **** was flat on the forward part and the corners were not comfy.

3) Hurst/Core short throw SHORT STICK. Stick was too low and awkward and the shift effort was dramatically increased.

4) Hurst/Core short throw LONG STICK. The current one I'm using in both my trucks. The length and position are perfect for the flip down middle seat arm rest thingy and it doesn't interfere with the cupholders or hit the dash or anything weird. It does require a little more effort than the factory shifter but it gives it a much shorter throw I'd say close to 20% reduction. It also makes a very satisfying feeling when it engages a gear, its evident you aren't shifting a honda. However there is something about the Hurst shifters that seems to transfer more vibrations into the cab. I think it's because they are a solid metal to metal connection directly to the gear box. It's more noticeable in my Tahoe than my RCSB but the trans were both built by different companies so that may have something to do with it. I'm looking at ways to make a nylon gear selector pivot ball pad to reduce some of the vibrations and noise.

 

Do you have a p/n for it? Or know where to get it? My shifter stick is still in great shape. I know that it has some sort of nylon cup thingy on the bottom side of the shifter that goes into a receptacle and that in turn is what moves the shifter rails about. I'd definitely want to stick the biggest clutch I can stick in there for later use when I swap the LS3/L92 in it. Could you post a few pics of this shifter?

 

let me go look in the garage... i know i just sold my Hurst Competition/Plus & stock 3500/4500 stick a month ago.
otherwise, centerforce & spec make clutches for the 3500. i personally run a LuK - with both the 3500 & 4500.

 

so if you want to keep the nv3500, just be easier on it & drive slower when towing. weight will burn it up if driving fast (hence why i have a 4500 now).
that said, the nv4500 is literally a direct swap. the only differences are a stronger clutch disk/pressure plate, reverse switch, and shifter base (besides an extra 100lb).

as for shifters, i fixed Dan's "crappy" 90s version base, and it shifts great now... but i swapped it for a Core shifter a month later (after he got more parts to build me one). it just needed another spring warsher or two inside. i still have it along with a new spacer plate, if you decide to swap & need it. it works with your stock nv3500 stick, and you'd never know anything was different. if you do go with a 4500 swap, i'd recommend using the shorter 95-00 GMT400 lid over the 01+ lid because it gives you a little more wiggle room without the factory 2" body lift.

i also have the stock nv3500 shifter base left, which won't be of any use to you (as it's the same as what you have now).

 

When you say lid, is this the top of the transmission where the shifter itself bolts to? I'm used to the old T-5 and T56 transmissions.