Doubler help

[odin]

Im currently running a TH400 NP205 (figure 8 fixed yoke)
Got my eye on a 203/205 doubler setup.

My question is..and yes Ive searched. But came up with conflicting info.
Will I need to change the output shaft in my TH400 to match the 203?

 

[4X4HIGH]

Im currently running a TH400 NP205 (figure 8 fixed yoke)
Got my eye on a 203/205 doubler setup.

My question is..and yes Ive searched. But came up with conflicting info.
Will I need to change the output shaft in my TH400 to match the 203?

Yes you will. You existing outpout shaft should stick out of the case by about 4.5" and it needs to stick out only 1.375" and of course you will also need a 400/203 adapter along with the 400/203 output shaft.

Here is all the info you need straight from ORD's website.

[FONT=Arial, Helvetica, sans-serif]GM TH400 Automatic Transmission:
If you have a TH400, there are three options for mating the 203 to your trans.[/FONT]
[FONT=Arial, Helvetica, sans-serif]1: Use a factory configuration. The TH400 was available with the NP203 in heavier duty trucks (3/4 and 1-ton generally) in approximately '78-'79. The factory configuration uses a 1 3/8" stickout 32 spline shaft in the TH400, a 32 spline input gear in the NP203 and a 1.1" adapter plate between the two, somewhat similar to the TH350 adapter plate. This is the shortest way to mate the TH400 and NP203.[/FONT]
[FONT=Arial, Helvetica, sans-serif]2: Use a TH400 that originally had an NP208 mated to it. This TH400 uses a 32 spline shaft that sticks out of the case about 2.5" and has an adapter housing that's about 2.5" thick. You'll use a TH400 version 32 spline input gear in the NP203 and re-drill and tap the face of the NP203 with the round bolt pattern to match up to the NP208 adapter housing. Benefits of this kit are the parts are quite common since the NP208 was very widely used with TH400 trannies. The drawback is the adapter is about 1.5" longer than the shorter factory configuration. [/FONT]
[FONT=Arial, Helvetica, sans-serif]3: Use a TH400 that originally had a NP205 behind it. This TH400 uses a 32 spline shaft that sticks out about 4.5". You'll need to use a factory TH400 to round pattern NP205 adapter housing that is 4" thick and once again, re-drill the front face of the NP203 to match the round pattern. The input gear will be the TH400 version NP203 32 spline input. Drawbacks to this system are the overall length with the 4" housing between the two and the expense of buying the factory housing. They're not common as used parts and typically must be purchased new. ORD can supply this adapter[/FONT]

 

[odin]

Thanks for the info.

 

[sweetk30]

shaft pic

also good reading here on ord doubler build.

http://coloradok5.com/forums/showthread.php?t=253000