Can I put a np203 in my 84’ K10 that originally had the 208?

[hayes1998]

I’m restoring my first truck, a 1984 Chevy Custom Deluxe 1/2 ton 4wd. Was a complete roller so I was looking at getting a transmission and transfer case. I believe this truck originally had a np208. I have found a th350 w/ a np203 for a relatively fair price. I was just wondering if this would even work for my truck, I’m aware that I might have to put the conversion kit and lockers but was just curious if this application would even work. Or if I just need to find a 208. Thank you

 

[GTX63]

Yes, a 203 will work. The last three 80s model squarebodies, an 83, and two 85s I have drug home had 203s in them, lol. I don't know why, but that is just what got swapped into them.
Grab the matching driveshafts if you can.

 

[geardaddy]

1984 k10 would have come with a np208. in 84 , only the 1 ton had a np205

 

[Old Guy Bill]

Going to a 203 will mean driveshaft changes.. and maybe adding a “Part time” Kit to not be full time FWD.
I wouldn’t even consider it.. I ditched the 203 to go to a 208 in the truck I’m building.
You can’t give a 203 away in my area, 208s are going for $100-200 depending on the input shaft spline count.

 

[hayes1998]

Going to a 203 will mean driveshaft changes.. and maybe adding a “Part time” Kit to not be full time FWD.
I wouldn’t even consider it.. I ditched the 203 to go to a 208 in the truck I’m building.
You can’t give a 203 away in my area, 208s are going for $100-200 depending on the input shaft spline count.

I’ve been trying to find a 208 in my area to no avail

 

[Cyrillious]

1984 k10 would have come with a np208. in 84 , only the 1 ton had a np205

That's interesting. I have an NP205 and mine is a k10 from 1980

 

[CalSgt]

That's interesting. I have an NP205 and mine is a k10 from 1980

205 was pretty standard for K-10 in 80,

 

[nvrenuf]

That's interesting. I have an NP205 and mine is a k10 from 1980

His statement specifically references 84 so there’s no conflict with what you have.

205 was pretty standard for K-10 in 80,

The 205 was the ONLY tcase used in 1980 regardless of truck / suv configuration.

 

[Grit dog]

Depends how much you’re gonna drive it and what your budget is.
T case should be essentially free if it’s a good rebuilt 350.
Worth more if you can get the crossmember, linkage and maybe some short bed driveshafts.
Otherwise that stuff costs money and you have to get a part time kit. (You don’t have to…I saw drove and fixed a couple of them back in the day. Work trucks that plowed snow in the winter. Never had a t case problem.)
But they aren’t as convenient as a drop in if you have all the outside parts already.

 

[Dooley]

I’m restoring my first truck, a 1984 Chevy Custom Deluxe 1/2 ton 4wd. Was a complete roller so I was looking at getting a transmission and transfer case. I believe this truck originally had a np208. I have found a th350 w/ a np203 for a relatively fair price. I was just wondering if this would even work for my truck, I’m aware that I might have to put the conversion kit and lockers but was just curious if this application would even work. Or if I just need to find a 208. Thank you

The coice of a 203 isn't all bad.
It gives you an option to run a pto if wanted. Seen them work winches on tow trucks.
1979 was a good year as they would have the improvements to the chain/gears that began during the 78 model year.

 

[Cyrillious]

His statement specifically references 84 so there’s no conflict with what you have.



The 205 was the ONLY tcase used in 1980 regardless of truck / suv configuration.

So k10, k20 and k30 used the NP205. Cool. What's the difference/upgrades from. 205 to 208? 208 more heavy duty?

 

[nvrenuf]

So k10, k20 and k30 used the NP205. Cool. What's the difference/upgrades from. 205 to 208? 208 more heavy duty?

In 1980 specifically, yes. No matter what 10, 20 or 30 series 4wd you had, it had an np205 (regardless of transmission as well).

As far as 205 vs 208, I don’t have any idea of each units max capacity but most will argue the 205 is the better unit. The 205 is an iron bodied gear driven case whereas a 208 is an aluminum chain driven unit, 205’s can be broken but it usually goes back to some lack of maintenance, etc. The 205 definitely wins for beefiness but it lacks in low range ratio, 1.96:1 vs 2.61:1 (iirc) in a 208.

 

[nvrenuf]

@Cyrillious with respect to upgrades the 205 wins; bigger yokes, twin stick abilities, upgrade shafts, upgrade cases, etc. At times, there are aftermarket 3:1 low range kits available however they are so expensive you’re really better off buying a product like a Magnum and combine it with a stock 205 with bigger yokes.

 

[Cyrillious]

In 1980 specifically, yes. No matter what 10, 20 or 30 series 4wd you had, it had an np205 (regardless of transmission as well).

As far as 205 vs 208, I don’t have any idea of each units max capacity but most will argue the 205 is the better unit. The 205 is an iron bodied gear driven case whereas a 208 is an aluminum chain driven unit, 205’s can be broken but it usually goes back to some lack of maintenance, etc. The 205 definitely wins for beefiness but it lacks in low range ratio, 1.96:1 vs 2.61:1 (iirc) in a 208.

I learned something new today. I have an idea the difference between the two. Thank you!