chevy transfer case for conversion

[bryanjeep]

YJ question from an XJ guy.

I already bought the SYE for my NP231, upgraded input shaft, and 700r4 transmission output shaft. All of this is meant for the NP231. Stupid me :evil: Now I am considering going for a Chevrolet transfer case with passenger side drop.

I am caught up with what I should do. I have already spent $320 on those parts. I can sell my SYE for probally $245 since it is still new in box. And the other parts are new but that would be hard to sell.

So, would it be better to find myself a good chevrolet transfer case that will bolt right to a TH350 or 700r4 or stick with the NP231. How much am I looking at here for the Chevy t case? Do they need a SYE on them with the SOA lift I am doing? How will I work the shifter and mount setup? Another reason I want to go to a chevy t case is because I can come across a passenger side drop front axle easier.

Anybody have a spare t case I can buy or even a transmission with it? Know anybody with one?

 

[White]

I would just look for another axle. 88-present t-cases are driver side drop. You need a pre- 88 . I would take a guess and say the sye would be needed, just for the larger t-case.

 

[bryanjeep]

I don't quite understand what you are saying. Are you saying keep the NP231 or find a chevy passenger side t case?

 

[White]

Iam saying keep your 231 and sye. Find another axle .

 

[bryanjeep]

Are they strong enough to hold up to 300 hp and 38" tires? I am thinking about ditching the idea of using a 700r4 transmission and going with the th350 transmission .

 

[White]

No, I would think a t-case designed for a motor with half that HP and torq would not hold up....
get a atlas.

 

[bryanjeep]

I have nowhere near that kind of money. I wish I could.

 

[White]

Not saying it wont work, Depends on how you drive. If you crawl it might be ok. If you hammer it , wont last long.

 

[Snitty]

if you are goin with big balls... you're gonna want a gear driven Tcase

 

[bryanjeep]

Is the NP205 or NP2208 gear driven? If not, which ones are?

 

[west747]

the 205 is gear driven but does not have a very low gear ratio in 4low. i beleive it is 1.72 to 1. that being said it is still the t-case i am ging to use when i put my 350 in. :lol:

 

[jps4jeep]

the 205 is gear driven but does not have a very low gear ratio in 4low. i beleive it is 1.72 to 1.

Very true
I think it was 1.92:1 but I really can't recall just now.
The NP205 was found in 73-87 chevy's with a muncie 4spd transmission where the first gear was a granny gear. combine the two low gear sets and the final drive was in the area of 4-1 It was also only found behind the 305, 350, and 400, not the 6 cyl. They are a passenger side front out put and also have a fixed yoke. AA makes an adapter to mate the NP 205 to a AX 5-AX15 but is expensive. The model NP 204 was found in the auto chevies of similar years but is still in use today in some chevies in some form or another. this T-case, depending on application, used a slip yoke!
The 88+ chevies that use the saganaw gear box I think use the NP205 but it is a different T-case, I think!

 

[Junkpile]

The model NP 204 was found in the auto chevies of similar years but is still in use today in some chevies in some form or another. this T-case, depending on application, used a slip yoke!

NP203. It was an iron full-time case, GMs stronger yet less efficient version of Quadratrac. I didn't know they used it after around 79-80.

bryanjeep-- I like your original idea of using the 700R4 and the 231 Tcase. I had mine converted to a HD unit, I think like the Dodge Rams use, and it made a world of difference in the durability of that case. The SYE will solve the output problems associated with that Tcase also.
1980+ Wagoneers are drivers drop.....what town doesn't have like a million of those sitting behind barns and in junkyards? First generation Broncos will get you a drivers drop D44 front and a 9" rear. Fullsize Ford axles will work too.
If you swap to a passengers side drop....don't forget about the Dana300 Tcase used in the 80-86 CJs. Plenty strong for your application and can be substantially beefed with aftermarket parts. It weighs alot less than an NP205 and has a better low-range ratio. Even if you don't have any confidence in the 231 and you wanted to stay with the drivers drop, a flipped D300 is hard to argue with.

 

[White]

add a twin stick to the 300.... ?

 

[jps4jeep]

NP203. It was an iron full-time case, GMs stronger yet less efficient version of Quadratrac. I didn't know they used it after around 79-80.

77-80, I had a 77 GMC Jimmy plow truck and it had the NP 203, Mine in particular was junk! And I know of one other person who had the same truck but was a 78 and his was junk too. You had to get out and lock the hubs for the 4wd to work the auto hubs for the awd was a option, (which neither my nor my friends truck had) also, when trying to get it into 4wheel low, it would lock out in neutral. you would have to rock the truck back and forth for ten minutes to sycronize the T-case just to get it into 4lo, and going back to 4hi was just as big as a pain!

Find a 77 bronco in poor condition (pretty easy thing to do huh) and use it's axles.

or find a 73-91 blazer of jimmy, for cheap money. pull everything out, motor transmission, T-case, axles, etc...

This is what I am doing. I have my old 77 blazer with 3/4 ton axles that I have not driven in 8 years, so I am going strip everything out, and put it into a YJ frame!

 

[redrooster]

E-mail Novak adapters to verify this, but I think with the adapter from the 700R4 to 231, you have a 23 spline transmission output. Your adapter should be 4 bolt holes on the transmission side and 6 on the t-case side. The Dana 300 is 23 spline with a 6 bolt mount. In other words, check with them to see if the length of the shaft and adapter are correct for using a Dana 300.
A Chevy 350, 700R4 and Dana 300 will be a great setup.