'76 K1500 NP203 to NP205 swap

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Zayshley

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Alberta, Canada
First Name
Gage
Truck Year
1976
Truck Model
K1500
Engine Size
6.6L 400sbc
I just recently bought a NP205, that was bolted to a 400/th350 in a '80 Blazer, that I plan in putting in my truck to replace the beat NP203 which has the locking hubs conversion kit. Besides drive shafts, is there anything else I need to make it work?
 

Bextreme04

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Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I just recently bought a NP205, that was bolted to a 400/th350 in a '80 Blazer, that I plan in putting in my truck to replace the beat NP203 which has the locking hubs conversion kit. Besides drive shafts, is there anything else I need to make it work?
It depends on what else you got with the NP205 and what its original application was. If I'm reading this right, the 205 came off a 400/TH350? What is the truck you are putting it in? Is it also a 400/TH350? Did you get the adapter and shifter with the 205? They don't have the same shifter, adapter, or linkage on the 203 I think.
 

Zayshley

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Location
Alberta, Canada
First Name
Gage
Truck Year
1976
Truck Model
K1500
Engine Size
6.6L 400sbc
It depends on what else you got with the NP205 and what its original application was. If I'm reading this right, the 205 came off a 400/TH350? What is the truck you are putting it in? Is it also a 400/TH350? Did you get the adapter and shifter with the 205? They don't have the same shifter, adapter, or linkage on the 203 I think.
My truck, 1976 GMC K1500, has the same set-up, 400sbc with a th350. It has the adapter and shifter, but im not sure what modification im suppose to do to the shifter. I've read that it would be a good idea to just do a twin stick set-up but idk if I wanna do that.
The NP205 came with the th350 it was bolted to, the cross member and the front driveshaft.
 

Bextreme04

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Eric
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1980
Truck Model
K25
Engine Size
350-4bbl
My truck, 1976 GMC K1500, has the same set-up, 400sbc with a th350. It has the adapter and shifter, but im not sure what modification im suppose to do to the shifter. I've read that it would be a good idea to just do a twin stick set-up but idk if I wanna do that.
The NP205 came with the th350 it was bolted to, the cross member and the front driveshaft.
If you mean that the 205 has the adapter and shift lever on it now, you shouldn't have to do anything else. I would rebuild the 205 front driveshaft with new u-joints and new CV guts and then put the entire adapter/205/shifter/crossmember/front driveshaft in your current truck. The rear driveshaft should be identical, except that the 205 driveshaft will need to be longer than the 203 driveshaft, since the 203 is longer than the 205. I would put it all in, then measure how much longer the rear needs to be and take your current driveshaft to a driveline shop to have it extended.
 

Zayshley

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Joined
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Posts
18
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Location
Alberta, Canada
First Name
Gage
Truck Year
1976
Truck Model
K1500
Engine Size
6.6L 400sbc
If you mean that the 205 has the adapter and shift lever on it now, you shouldn't have to do anything else. I would rebuild the 205 front driveshaft with new u-joints and new CV guts and then put the entire adapter/205/shifter/crossmember/front driveshaft in your current truck. The rear driveshaft should be identical, except that the 205 driveshaft will need to be longer than the 203 driveshaft, since the 203 is longer than the 205. I would put it all in, then measure how much longer the rear needs to be and take your current driveshaft to a driveline shop to have it extended.
Alright. The rear driveshaft needs to have a slip yoke since its an '80 transfer case unlike the older ones with a fixed yoke so I need to get a new shaft with one.
 

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