1976 K10 Transmission Swap Questions-NV4500 and Clutch

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70ss496

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Lone Jack MO
First Name
Matt
Truck Year
1976
Truck Model
K10
Engine Size
350
My son and I are starting on a 1976 K10 Project. The truck is all original right now and came from the original owner. Truck has a 350/SM465 4-Speed and Factory 3:73 Gears, and NP205 Transfer Case.

We are planning on installing a 6.0L LS Motor and originally I planned on just leaving the SM465 behind it. I'm really contemplating and wondering how involved it would be to go ahead and install a NV4500. I'm sure there are plenty of people that have done this, what all does it entail? The main question I have is I've never messed with a hydraulic clutch, and I'm assuming I will have to swap to a hydraulic clutch with the NV4500?

Also, is there a certain year of NV4500 that is better or fits better than another? I've found several out of mid-90's 3/4 and 1-ton pickups but haven't pulled the trigger on them yet.

Thanks in advance, Matt.
 

SquareRoot

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85
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K20
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Your talking my language. I have done a few. I have several threads on here about it. If you search under my name you will find them. Basically, I'll give the bottom line to get you started.
1. Any NV4500 you find will need rebuilt. Figure $800 for a quality kit if you do it yourself. It's fairly involved and requires some special tools.
2. 93-94 have a very low 1st gear. Depending on your rear gears, it's not fun as a daily driver.
3. 95 and newer have a much better 1st gear and some notable upgrades.
4. The special fluid is a MUST or you will destroy the carbon fiber syncros. Fluid is 5 quarts @ $20/quart.
5. Your mechanical linkage pedals wont work without modification. You need 85-87 specific pedal assembly. They are hard to find and $$$.
6. You will need an adapter from AA to mate with your figure 8 t-case. T-case input shaft must be a 32 spline to match the NV4500 output.
7. You will likely need a new clutch and flywheel.

It adds up quick and it is a lot of work. However, it was worth it but I wouldn't do it again the way I did.
I STRONGLY recommend buying a complete kit from Advanced Adapters. It will save you time, money and you get a warranty. As nice as the 4500 is with its buttery smooth shifting and battle-tank strength, it has it's quirks. It's noisy. You will hear the gears. It shifts like a dumptruck. Speed shifting is not gonna happen. It really comes down to what your expectations are.
 

Grit dog

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454, 350
^All good advice.
Save for the certainty that any one you find will need to be rebuilt. You must mean, it “may” need to be rebuilt or it would be wise (maybe?) to rebuild.

@70ss496 heres some more advice. If you’ve found “several” NV4500s and they’re reasonably priced, buy them ALL. And sell the ones you don’t need and make a profit.
They are generally very hard to find unless buying retail.
Heck, over 25 years ago they were hard to find used and brought good money. I bought one in 1995 because I thought the Getrag was going out in my truck. Ended up not needing it and when I went to sell it, had people beating my door down for it. Ended up with a bidding war in my garage!
 

70ss496

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Location
Lone Jack MO
First Name
Matt
Truck Year
1976
Truck Model
K10
Engine Size
350
Thanks guys. I'm still doing some research and will look up the other posts.
 

derekp

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south eastern PA
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derek
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1997
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suburban
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I realize this is older thread. My project truck Im trying to swap sm465 to 96 nv4500 internal throwout
My problem - hought the original clutch (new - no road time - project truck purchased from someone) would work fine.
Not so lucky - while the spline and pilot bearing and inut shaft length all fit up ok, the (new) hydraulic internal throwout (when trans and its bell housing are installed) is not being compressed it just "makes contact" with the diaphram clutch levers. I ordered a clutch for a 96 truck/nv4500 and the pressure plate that showed up had even "shallower" fingers and overall height.
My press plate has "hi" fingers ( i can get measurements of overall height late on)
It appears that the 4500 throw out needs to be pushed back as much as up to an inch to compress its built in spring, my setup does not do that, the throw out just touches the diaphram fingers
Im stuck - any suggestions appreciated. Budget prevents me from buying $$$ parts
Thanks in advance for any insight on this
FYI its not a squarebody, but you guys seem to have more posts on this topic than other sites.
 

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