putting d300 in xj behind aw4

so what all is involved? i have already picked up the new tranny with the 23spline output, and i picked up a d300 today, i am getting ready to order an adaptor ring from novak, i think the ring allows you to clock the case up a little bit (im thinking about 10 degreese would be suffice so the case doesnt stick down??)
i have the passenger side drop front 60, and matching rear 70 but anyway.

i have a couple questions about the np231-d300 swap.
how do you guys re-route exhaust? simply take it down drivers side from manifold and go back? where would be a good place to cross back over?

how much will i have to chop on transmission tunnel?


anyone ever made there own twin sticks? any advice?
will the sticks need to come toward the transmission vs. straight up?


anything i am missing here? just looking for common problems before i tackle the project.

can i consider it a 1ton xj now? i know the d300 isnt actually one ton but it still sounds really cool :greensmok

I just got back from testing my 300 for the first time. Finnished it up Friday night and took it to Tellico Awesome! I can give you lots of details, but for now I am going to sleep! dave

35xj said:

I just got back from testing my 300 for the first time. Finnished it up Friday night and took it to Tellico Awesome! I can give you lots of details, but for now I am going to sleep! dave

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care to share?

Are you going to flip the case? What front axle are you gonna use? I did a non flipped 300 with a waggy 44 front. The bracket kit is kinda tricky with the passenger drop. We had to cut up an RE kit to make it fit. You will have to cut a pretty good chunk of floor out to make the case fit and I clocked mine in the lowest position. In the upper 2 positions the front flange was intruding through the floor! Driveshaft clearence is good. no problems so far. We swapped the trackbar from left to right frame rail. this has caused some REALLY wierd handling problems, so a 3 link is in the works. You need a longer pitman arm(waggy) to regain good steering. As far as levers, get good ones. I bought some from e-bay. I think i will be ordering some from Currie soon. Are you planning to do a 4;1 kit? its awesome! We removed the shift interlock pins in my case to give me front high range. its usefull, but it makes the right lever kinda hard to feel the 3 positions. hope this helps, i am slowly putting together a write up on the project. if you have any questions let me know. dave Special thanks to jody treadway of WNCCUSTOMJEEPS.

just reread your post. front 60. cool! as far as the exhaust. I ran mine from the header down the driver side, over the crossmember and out right before the rear axle. dave

We swapped the trackbar from left to right frame rail. this has caused some REALLY wierd handling problems, so a 3 link is in the works.

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OMG, a track bar that runs the OPPOSITE direction of the steering. That's a new one!

Why didn't you just put the track bar mount on top of the differential housing? It would be about the perfect height for a high steer setup......

CRASH

YEAH.... seems so obvios after the fact. :doh: It really did seem like a good idea at the time.

get an atlas... the money is worth the peace of mind imo
if i could go back i wouldn't have built my 231 (polished turd)

this project is on a really tight budget, i know that by the time i am done i could have had an atlas, but imo a well built d300 is as good as an atlas for my application (im ready for flames now )
i am going to run a 4:1 eventually but i have been without the jeep for quite a long time and i want to get a couple runs in before summer is over, then add the 4:1 to the list for winter projects.

i was thinking about taking a plasma and cutting my transmission tunnel off, getting everything into position and then either weld the old one back on or make a new tranny tunnel.
i plan on raising my engine about .5"-1", i will run a cowl inducted hood, to clear the engine, cut on the firewall to accept the higher bell housing, and probly make my own tranny tunnel to accept the higher trans, and the new d300.


35xj, what bracket kit are you talking about?

thanks for the help

xj_punk said:

get an atlas... the money is worth the peace of mind imo
if i could go back i wouldn't have built my 231 (polished turd)

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Where is anyone talking about building up a 231?

-Scott

sintax said:

Where is anyone talking about building up a 231?

-Scott

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i was saying that i regret building up a 231... just like you might regret building a d300! just buy an atlas, it is not much more than twice the cost

so what advantages does an atlas have over a twin sticked d300 with a 4:1 low?

i understand the atlas might be stronger, but i have personally and have seen people beet on the 231 all day long and hard and it has always held up pretty well, imo the strength of a d300 shouldnt be an issue (i can always upgrade outputs later) i havent read about anyone breaking a d300 (now you guys are going to show me a thousand posts of people breaking them)

arent most atlas' 4:1 low? i know they make a 5:1

i still have control over fwd or rwd or 4wd

i know the atlas has more advantages, but i dont think i could take advantage of every single option the atlas has.

BTW i will still have less then half in my d300 after it is installed and has a 4:1 then what an atlas costs

the d300 is an old case so you have to rebuild it... the atlas has everything stronger and comes with twin stick... you can get a few diff gear ratios like 3.8, 4, 5 and i think 3.0...you have to clock the 300 and upgrade input and output and get a 4:1
a 4 to 1 is what, 900 bucks? add a rebuild kit and shafts and you will be about 1500 or so won't you? what about a clocking kit and doublestick kit? seems like you will be pretty close to 2k.
an atlas is like 2500 bucks give or take a little and it comes with everything!!

think about it, i overlooked it as an option when i built my 231 and it is my biggest regret

an D300 would cost just a couple hundred to leave the stock gears, then about $1000 total with a 4:1. An Atlas will run over $2000. The D300 is half as much, and you can spend the money in 2 stages, d300 has it's reasons. now throwing money at a 231 does seem pointless: $1k for 4:1 gears, 300 for SYE, then money for HD chain and 2lo...

xj_punk said:

the d300 is an old case so you have to rebuild it... the atlas has everything stronger and comes with twin stick... you can get a few diff gear ratios like 3.8, 4, 5 and i think 3.0...you have to clock the 300 and upgrade input and output and get a 4:1
a 4 to 1 is what, 900 bucks? add a rebuild kit and shafts and you will be about 1500 or so won't you? what about a clocking kit and doublestick kit? seems like you will be pretty close to 2k.
an atlas is like 2500 bucks give or take a little and it comes with everything!!

think about it, i overlooked it as an option when i built my 231 and it is my biggest regret

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the case has had all the seals and bearings replaced $200 <- including purchase of t-case
the adaptor for the tranny will allow to clock a little bit, im not flipping the case $180
double stick `$20 (fabbing own)
4:1 has been found for $700

xj_punk said:

upgrade input and output and get a 4:1
a 4 to 1 is what

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although this is the first time i have read about this...

anyway around the HD inputs and outputs for the 4:1 to work?

mad maXJ said:

an D300 would cost just a couple hundred to leave the stock gears, then about $1000 total with a 4:1. An Atlas will run over $2000. The D300 is half as much, and you can spend the money in 2 stages, d300 has it's reasons. now throwing money at a 231 does seem pointless: $1k for 4:1 gears, 300 for SYE, then money for HD chain and 2lo...

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Thats whats Im talking about. I dont like to large and CHARGE, I like stages.

A d300 is lighter then an atlas...
An atlas 5:1 would be nice, and easy to install, but at a Huge cost.

Now a used Atlas at a good reduced price is an option to keep an eye out for, when planning your d300 build!

if it helps, 4:1 has been found for about $500.00 :viking: I think you'd be CRAZY to go through all the trouble to lift the entire engine/tranny. I built a new x member that lifted the case about .5 inches. This way you cut out much less structure by only cutting a hole in the tranny tunnel. My case still sits up inside the frame rails and does not hang below at all. From my research and testing the front 300 output is pretty strong, but i did upgrade the rear to the terra kit. hope this helps. dave

35xj said:

if it helps, 4:1 has been found for about $500.00 :viking: I think you'd be CRAZY to go through all the trouble to lift the entire engine/tranny. I built a new x member that lifted the case about .5 inches. This way you cut out much less structure by only cutting a hole in the tranny tunnel. My case still sits up inside the frame rails and does not hang below at all. From my research and testing the front 300 output is pretty strong, but i did upgrade the rear to the terra kit. hope this helps. dave

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raising everything is just an idea i am exploring right nowk, but since i am already going to have the tranny tunnel cut up i was figureing to raise everything.


care to tell me where you got the kit for $500? does it require upgrading the outputs?

thanks for the help guys