output shaft length on th400 for 203?

[muddybuddy]

what length output shaft do i need on the back of the th400 to bolt up to a 203? my buddy has a yard and ive noticed online that there are a couple different output shaft lengths. thanks

 

[muddybuddy]

anybody have an idea? or at least what years i need? i think its like '75-'81 or so but im not sure. if anybody know that would be much appreciated cuz i think theres like a 2.5" 3.5" and 5" (that sticks out of the trans).

 

[nvrenuf]

It wont be any newer than a 79, that was the last year of the 203. Not sure what the first year is. The tailshaft will only stick out of the case like 1.5", UBER SHORT.

The 4.5" stick out is for a 2wd or figure 8 205 set up.

The 3.5" stick out is for a 85+ round pattern 205 or a 208/241.

 

[muddybuddy]

thanks john, so will all 4wd th400 before '80 have the 1.5"? i figured itd probably be the shortest of the 3 but wanted to make sure

 

[4X4HIGH]

Here, 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]

 

[muddybuddy]

thanks scott. ive got the factory 400/203 adapter so i just need a tranny. im sure i could get any tranny and then swap the outputs, but that would involve taking the tranny apart, so '78 or '79 is what im lookin for

 

[Greg72]

You've been on CK5 long enough to know that when someone posts up a bitchin' reference photo or document, you always SAVE a copy to your own PC....

Like this one:

 

[muddybuddy]

greg, that is bitchin reference photo, i was looking for something like that on google but couldnt find anything. right click save as thanks greg

i was also trying to find all the measurement s for all the chevy trannys to get an idea about drivetrain length and a general idea about driveshaft measurements. i found one before but i forgot to save the pic

 

[Greg72]

You mean something like this......???

Your "SAVE AS" function is getting workout today.

 

[muddybuddy]

thanks a ton greg! so looks like im gona "lose" 12 more hp time to build the motor too to compensate for it