I have started on my venture to get the shortest doubler setup possible. I am starting out with the C4 to Atlas shorty adapter. It is 3" and has a 27 spline output. You need to machine the governor housing down, so you will need to be running a manual shift valve body. I am using a Ford 203 reduction box to get the round bolt pattern (more on this in a moment) and a 27 spline Chevy 203 input shaft to mate up to the AA kit. I will be using a JED's doubler adapter which will run around 3" long and will be going with a Ford 205 tcase. The total length of these components is 23 3/4". The stock adapter and EB20 ran around 17 3/4". So basically, I am adding just the length of the 203 case to the driveline.

So far, things I need to get machined: I have to get the governor machined down, and I have to machine the bearing retainer down on the 203. On the adapter, only 4 of the 6 holes line up (it is drilled for an Atlas) so I am thinking of just mocking it up under the jeep and clock it to where I want and then drill 6 new holes so I get the best placement possible. I will add some pics of this setup as it starts to go together. I will be getting the governor housing and bearing retainer machined down early next week and maybe even get the holes drilled in the adapter for the 203. Next paycheck.....order the doubler. :)

Ken

Here are the pics with the adapter installed...temporarily, because I still have to counter sink the governor housing for the bolts that hold it on.

Some more pics...

http://www.pirate4x4.com/forum/attachment.php?attachmentid=194184&stc=1

http://www.pirate4x4.com/forum/attachment.php?attachmentid=194183&stc=1

and the last few for now...

http://www.pirate4x4.com/forum/attachment.php?attachmentid=194185

http://www.pirate4x4.com/forum/attachment.php?attachmentid=194186

I likey, now can I get prices on this stuff you have gotten or had done, etc?

The only item I have purchased is the AA C4 to Atlas shorty adapter. Talk to Scott at rock buggy supply in the vendors forum for the adapter. He hooked me up with a screamin' deal. I had to get the governor machined down (you need to run a manual valve body with this setup) which cost me a 6 pack. :) Next is up to order a doubler setup from JED's machining. It will be using a 27 spline input shaft (the AA kit upgrades the output shaft on the C4 from 26 to 27 splines) and will be stuffed in a Ford (round 6 bolt pattern) np203. I will need to relocate some new holes in the adapter so I can clock it to where I want it. :) You could also go to a D300 if you were running passenger drop, or flipped it. I will be posting more pics as I go along. It will take some time, do to trying to buy a piece of land and build a house along with trying to finish it up. :D

Very interesting project. I've been gathering parts to do a doubler in my EB so this is very timely. Keep the updates coming!

Dusty

Will do. :)

I am toying with the idea of making my own Klune style crawler box which would make a doubler setup even shorter (not to mention lighter) plus give it a 2.7:1 ratio rather than 2 2:1 ratios and a 4:1. .02 I just need to grab a 231/241 case with a 27 spline input for some R&D. :)

No pictures to add yet, but I swapped the 27 spline GM input shaft into the Ford 203 reduction box. Bolted it up to the tranny. All 6 holes lined up on the adapter so that was a bonus. :) The bellhousing to the back of the 203 box is a shade under 26". I think using the JEDs doubler and the 205, the total length will be around 41.5" long. I believe that is shorter than my AX5 and non SYE'd 231. I have to double check the original numbers. I will post some pics of it early next week.

Ken

SO I should keep this Chevy 203 around then to use for a doubler behind a c4?

Edit: I see you're saying in the first post to get the Ford 203 Range box for the round pattern but using the Chevy input. Now question stands as this....I am not too familiar with the 203 but learning fast, output shaft on the c4 works with the chevy 27 spline input or what?

Next is up to order a doubler setup from JED's machining. It will be using a 27 spline input shaft (the AA kit upgrades the output shaft on the C4 from 26 to 27 splines) and will be stuffed in a Ford (round 6 bolt pattern) np203.
kpj, great stuff! Keep the pictures coming! You've my total attention.

One note, the Stock C4 has a 28 spline output, for both the 2wd and 4x4 version. (The 2wd is just much longer, however could be resplined for 27 splines)

http://www.4x4axleinfo.com/img/C4/Other/C4_tail_2wd_vs_4wd.jpg
http://www.4x4axleinfo.com/img/C4/diagram/C4_tailshaft_measurements.jpg

Can you take more pics of the shorty adapter? Can you quick take it off in section? (Might as well ask)

Sure thing. I am heading out camping today for the weekend, but I have to disasseble it to put a couple of input seals in the 203 and will grab some more pics then. I can try and get a couple of pics of the governor housing machined down, and of the adapter itself.

Sure thing. I am heading out camping today for the weekend, but I have to disasseble it to put a couple of input seals in the 203 and will grab some more pics then. I can try and get a couple of pics of the governor housing machined down, and of the adapter itself. :grinpimp: :beer:

Here are those pics I promised ya.

Here is the Ford 203 reduction box bolted up to the C4.
http://www.pirate4x4.com/forum/attachment.php?attachmentid=197521

Here is a pic of the steel plate adapter, the shaved down governor housing and the 27 spline shaft installed.
http://www.pirate4x4.com/forum/attachment.php?attachmentid=197522

A different angle of the above. The governor housing got shave down to around .535", the dowel pin that the "parking pawl" goes to (on the left side of the adapter) had to get cut down as well about 3/16" to clear the steel adapter.
http://www.pirate4x4.com/forum/attachment.php?attachmentid=197523

This is the C4 side of the adapter that aligns itself with the rabbit.
http://www.pirate4x4.com/forum/attachment.php?attachmentid=197524

Here is the tcase side, it gives me a little bit of an option with clocking it, not much, but I should be all set with my current flat skid plate.
http://www.pirate4x4.com/forum/attachment.php?attachmentid=197525

Here are some pics of the machined down bearing retainer for the 203. It was required to be machined to fit in the aluminum adapter of the C4.

http://www.pirate4x4.com/forum/attachment.php?attachmentid=197531

http://www.pirate4x4.com/forum/attachment.php?attachmentid=197532

nice set up.

Thank you. I am hoping to have the doubler adapter within a couple of weeks. Stay tuned for more. :)

Thank you. I am hoping to have the doubler adapter within a couple of weeks. Stay tuned for more. :)
Good stuff!

YUP I am REALLY liking this. A cheaper way than the WH unit!

YUP I am REALLY liking this. A cheaper way than the WH unit!

And the adapter is half is long. :) The WH kit is 6.5" long, while this adapter is a shade under 3". :)

Does anyone know if the EB20 tcase has the standard 6 bolt round pattern as the 205, 203, 300 tcase's? I am going to put off ordering the doubler adapter for a little while and see if I can't get someone to custom machine an alluminum adapter that would be around 1.5" long to go from the 203 to a np205 or d300. I am starting to lean towards the d300 for it's length and weight savings over the 205.

The reason I ask is because I have the c4 to EB20 adapter (don't have the d300 to check) and I was considering dropping the adapter and the 203 off to have a machine shop start making it for me. :) I imagine it would be ALOT cheaper (I have a machinist friend that is CHEAP!!) than doing the WH kit as well. I can have Wagonner Machine Shop cut down my 203 output shaft for around $100. :) If this does work out, I may have him make a couple of the adapter's for some POR friends. :)

Ken

Scratch that last post. I ordered up a Northwest Fab 203 to 205 doubler setup today and will get around to installing it in a couple of weeks. I will definetely be posting up some bling pics of the adapter and the overall length. The adapter is 3" long. :D

Ok I got my price from RBS and I am liking.

SO this C4 to atlas adapter bolts to the Ford 203 with some bolt hole relocation, correct?

I understand the rest of the 203-205.

No bolt hole relocation was required. I thought I was going to have to egg out 2 holes, but everything lined right up. You will need to take your governor housing down to .5xxish thick and grind the pin the that holds the parking pawl in place. I have access to the tooling so it worked out pretty good. :) You will also have to machine down the 203 input bearing retainer. I show it a couple of the pics. :)

Ken

Oh yeah, I have the 203 basically in the stock location. I don't know if the holes are symetrical or not, so if you go to clock the 203, you may need to do some drilling. I believe the 203 uses the standard round 6 bolt pattern, so you should be able to clock in any position. I have the clearance to run it straight down, so I did for ease. :)

Ken

Oh yeah, I have the 203 basically in the stock location. I don't know if the holes are symetrical or not, so if you go to clock the 203, you may need to do some drilling. I believe the 203 uses the standard round 6 bolt pattern, so you should be able to clock in any position. I have the clearance to run it straight down, so I did for ease. :)

Ken
About the only this could get better is if you placed paper over the adators and did a rubbing. :grinpimp: :D :p

My Northwest Fab doubler adapter will hopefully be shipping out tomorrow so I should be able to update the pics a little next week. After I get everything straightened out on the bench, it will get installed and test fired. :)

Just got the NWF today and will hopefully be installing it this weekend. :grinpimp:

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203542

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203541

Here are some assy'd pic's. Just need to get some triple sticks in there, and I may clock the 205 up a tad more, have to see how much metal I need to sawzall out of the way. :grinpimp:

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203802

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203803

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203804

More pics later. :)

Here are some more measurement's of the different components. :)

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203812

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203813

http://www.pirate4x4.com/forum/attachment.php?attachmentid=203814

I checked my original measurements for my TJ with the AX5 and an SYE'd 231 and the length was 38.5". I am not going to complain about the extra 3" of drivetrain length with the doubler installed. :) Right now, I have about 18.5" of driveshaft with the stock d35 under the back. I am figuring I am going to lose atleast 3" of shaft when the 14bolt goes under it, but I am going to counteract that by sliding the axle back a few inches. I also have a HP60 center chunk that I am going to try and turn into a rear end over the winter, which would alleviate any driveline angle or length concern I have.

Have an update?

How is this holding up, working out for you?

Unfortunately, I have since sold the TJ and basically parted all the parts out with never running the 203/205 behind it for financial and ADHD reasons. :laughing: I have recently just got back to putting a rig back together (a ~94" wb CJ-5) and am going with a 350/350/300 setup because it was convenient, but I regret not using the Ford stuff for the weight and past experience. That 5.0/C4 combo ran like a raped ape and was simply the most fun drivetrain I have ever owned (when I had the EB20 hooked to it). I hope I can get the TPI350/th350 to run the same way.

There are plans on using a 5.0/C4/d300 setup (using the same AA adapter) and stuff them into an old flatfender w/toy axles or 9" hybrid axles next summer/fall after the CJ is built. But until then, I have nothing to add on the project. :(