What type of transfer case do I have in my truck ?

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boltbrain

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If a 205 bolts to a NV4500 what year NV4500 will I need of course it will be bolting to a 350 4 barrel....
There are several different types of NP205 with various input splines, types, and bolt patterns. A figure 8 NP205 needs about a $600 adapter kit to bolt up properly. The kit linked below is specific for 10 spline input, but there are multiple kits for the various input types on the figure 8 units. https://www.polyperformance.com/adv...FID8klWgd9lSysJtSbCyTEIJ7UfR_1HxoCj94QAvD_BwE

The other option would be a round pattern NP205 from an 85-up 1 ton truck. There are a few of those as well, and it looks like you would need about $150 in parts and some machine work to get them to fit. Here's a thread on Pirate 4x4 talking about those two options. https://www.pirate4x4.com/threads/gm-nv4500-to-np205-round-pattern-with-32-spline-input.2706862/
Probably need an adapter, possibly a different input shaft, depending on what transmission is currently in it.
If a 205 bolts to a NV4500 what year NV4500 will I need of course it will be bolting to a 350 4 barrel....
The 205 doesn’t bolt to a NV4500 and they have different splines. The $600 adapter that Advanced Adapter sells comes with a spline adapter sleeve that’s 32 tooth on the NV4500 end. The NV4500 case is about 13” long, and the GM adapter that comes with it is about 7 or 8 inches long, it’s got 5th gear in it. the mount is in the bottom of that adapter. So then you bolt the 7 or so inch AA adapter to that GM adapter, and I don’t know how that’s supposed to work, because the stick is only 4” from the seat to begin with. Im calling AA tomorrow after I look online at their diagram. You’ll also need their bell because a NV4500 doesn’t bolt to the bell you have. You can use your flywheel but only if you get it machined to accept the bigger NV4500 pilot bearing. AA has a bell that’s machined for that. Don’t mean to sound like a AA salesman but I’ve been talking to one of their salesmen and might buy their stuff after I find out if the stick has to move back 7” or not.
 

boltbrain

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The 205 doesn’t bolt to a NV4500 and they have different splines. The $600 adapter that Advanced Adapter sells comes with a spline adapter sleeve that’s 32 tooth on the NV4500 end. The NV4500 case is about 13” long, and the GM adapter that comes with it is about 7 or 8 inches long, it’s got 5th gear in it. the mount is in the bottom of that adapter. So then you bolt the 7 or so inch AA adapter to that GM adapter, and I don’t know how that’s supposed to work, because the stick is only 4” from the seat to begin with. Im calling AA tomorrow after I look online at their diagram. You’ll also need their bell because a NV4500 doesn’t bolt to the bell you have. You can use your flywheel but only if you get it machined to accept the bigger NV4500 pilot bearing. AA has a bell that’s machined for that. Don’t mean to sound like a AA salesman but I’ve been talking to one of their salesmen and might buy their stuff after I find out if the stick has to move back 7” or not.
Meant: AA has a flywheel that’s machined for the pilot hearing, not a bell
 

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Thanks for the help...and informative info keep me posted....
But if I need to go with the nv3500 instead of the 4500. Then that may be the way I go
Gotta figure all this out...
 

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The 205 doesn’t bolt to a NV4500 and they have different splines. The $600 adapter that Advanced Adapter sells comes with a spline adapter sleeve that’s 32 tooth on the NV4500 end. The NV4500 case is about 13” long, and the GM adapter that comes with it is about 7 or 8 inches long, it’s got 5th gear in it. the mount is in the bottom of that adapter. So then you bolt the 7 or so inch AA adapter to that GM adapter, and I don’t know how that’s supposed to work, because the stick is only 4” from the seat to begin with. Im calling AA tomorrow after I look online at their diagram. You’ll also need their bell because a NV4500 doesn’t bolt to the bell you have. You can use your flywheel but only if you get it machined to accept the bigger NV4500 pilot bearing. AA has a bell that’s machined for that. Don’t mean to sound like a AA salesman but I’ve been talking to one of their salesmen and might buy their stuff after I find out if the stick has to move back 7” or not.
85 and newer 205 DOES bolt to the nv4500. I have done it. You may need a spacer IF the 205 input shaft is the long version commonly found in these t-cases. You can also swap to a short input and eliminate the spacer. Lots of disinformation being tossed around in this thread.
 

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The 205 doesn’t bolt to a NV4500 and they have different splines. The $600 adapter that Advanced Adapter sells comes with a spline adapter sleeve that’s 32 tooth on the NV4500 end. The NV4500 case is about 13” long, and the GM adapter that comes with it is about 7 or 8 inches long, it’s got 5th gear in it. the mount is in the bottom of that adapter. So then you bolt the 7 or so inch AA adapter to that GM adapter, and I don’t know how that’s supposed to work, because the stick is only 4” from the seat to begin with. Im calling AA tomorrow after I look online at their diagram. You’ll also need their bell because a NV4500 doesn’t bolt to the bell you have. You can use your flywheel but only if you get it machined to accept the bigger NV4500 pilot bearing. AA has a bell that’s machined for that. Don’t mean to sound like a AA salesman but I’ve been talking to one of their salesmen and might buy their stuff after I find out if the stick has to move back 7” or not.
Factory nv4500 located the shifter in the factory location of the factory 4 speed trans. I have done it.
 

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Pics of my 4500 swap for reference.
 

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SquareRoot

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A few more.
 

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boltbrain

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My 205 has 8 bolts in a figure 8 pattern, whereas my NV4500 has six, but I stand corrected. I should have said my 79 205 wont bolt to my 05 nv4500. Which is why Advance Adapters developed their NV4500 to NP205 adapter. You can check it out on their website, it’s part # 50-0217, I think. I haven’t actually seen it yet.
 

boltbrain

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Factory nv4500 located the shifter in the factory location of the factory 4 speed trans. I have done it.
I was referring to the T case shifter not the 4500
 

boltbrain

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85 and newer 205 DOES bolt to the nv4500. I have done it. You may need a spacer IF the 205 input shaft is the long version commonly found in these t-cases. You can also swap to a short input and eliminate the spacer. Lots of disinformation being tossed around in this thread.
Thanks, to a shorter input and then what? Where are those shorter inputs available? If I use an AA adapter it moves my T case stick back under the seat so I’m very interested.
According to AA the Nv4500 has two spline tooth numbers on it’s output shaft and their adapter requires cutting about 4” off it and use the inner teeth instead of the outer 32 teeth. And then they put an adapting sleeve over both shafts. I’d much rather use the shorter T case shaft
 

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Thanks, to a shorter input and then what? Where are those shorter inputs available? If I use an AA adapter it moves my T case stick back under the seat so I’m very interested.
According to AA the Nv4500 has two spline tooth numbers on it’s output shaft and their adapter requires cutting about 4” off it and use the inner teeth instead of the outer 32 teeth. And then they put an adapting sleeve over both shafts. I’d much rather use the shorter T case shaft
An 84 and earlier NP205 that was bolted to a TH400 will have a figure 8 pattern on the T-case and a short 32 spline input shaft. The adapter for that setup has the T-case shifter mount cast into the side of it. You need 4-1/2" of output shaft from the 6-bolt mounting surface on the trans to connect straight to this setup if you machine the index ring on the round side of the adapter .01" larger diameter. The 85-up NP205 uses a round pattern and a long 32-spline input shaft. This allows a shorter output shaft on the transmission.
 

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