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FNG - What application has the 205 I want?

PavementPounder

PavementPounder

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I have a 1987 Suburban that I have already swapped a D60/14bFF (with Ford dual-piston outers :rolleyes:) into and want to continue my 1-ton conversion. I'd post a picture or something, but I'm a FNG and can't yet.

My driveline is currently the stock 700r4/208. What model/year donor vehicle would have the correct 205 to run behind my 700r4?
 
There is no factory 700/205 combo. You'll need a 205 and adapter from a th350 and then add a spacer (1", I think) to make it work. I'm not sure if there are right or wrong 700 tailshafts but I'm sure someone more familiar with the swap will chime in.
 
Like nvrenuf said, you need a 205 from a TH350 along with the adapter and then you'll need the techpak fitzall spacer (7Q-35A). There is some rumor that you might still need to trim a small amount from the tailshaft of the trans output if the shaft bottoms out in the 205 input gear.
 
As for the correct NP205, most 1973 4 wheels drives use the NP205, and all 1980's (although they use a slip yoke on the K10 an K20's I believe).

Martin
 
That the setup I have. (700R4/205) Did it about 16 yrs ago. I think I used an adapter plate for a 350 and an output shaft in the trans from Advance Adapters. I also used the bolt on rear output instead of the slide in yoke.
 
Normally I would aim for a fixed rear yoke, but a slip may be fine for how I use the truck. I guess I was expecting the 205 to only have come behind the TH400's. Just to be clear, I should be able to find both the 700r4 NP adapter and case behind a TH-350? Will the TH-350 205 be a 32-spline input, or will it match my current 700r4 (27-spline?)? Or the adapter is a TH-350 item and the case is a TH-400 item?

Replacing the 700r4 output is also probably fine. The trans is going to have to be rebuilt anyway whenever I decide to address the tired motor. I have the one in the truck to beef up, or a 2wd unit from a diesel van to choose from. I was told that the van trans is a non-electronic lock-up? Not sure if I want to bother with that and may save it for replacing a 3-speed in something else.
 
82355 said:
As for the correct NP205, most 1973 4 wheels drives use the NP205, and all 1980's (although they use a slip yoke on the K10 an K20's I believe).

Martin
Click to expand...

Wrong Marty it 73 that has 205s (frank), all 74s had 203s (I thought).
 
Quote:
Originally Posted by 82355
As for the correct NP205, most 1973 4 wheels drives use the NP205, and all 1980's (although they use a slip yoke on the K10 an K20's I believe).

Martin

Wrong Marty it 73 that has 205s (frank), all 74s had 203s (I thought).

That is what I wrote John . . . .
 
PavementPounder said:
Normally I would aim for a fixed rear yoke, but a slip may be fine for how I use the truck. I guess I was expecting the 205 to only have come behind the TH400's. Just to be clear, I should be able to find both the 700r4 NP adapter and case behind a TH-350? Will the TH-350 205 be a 32-spline input, or will it match my current 700r4 (27-spline?)? Or the adapter is a TH-350 item and the case is a TH-400 item?

Replacing the 700r4 output is also probably fine. The trans is going to have to be rebuilt anyway whenever I decide to address the tired motor. I have the one in the truck to beef up, or a 2wd unit from a diesel van to choose from. I was told that the van trans is a non-electronic lock-up? Not sure if I want to bother with that and may save it for replacing a 3-speed in something else.
Click to expand...


you need the 27 spline np205 because youre 4x4 700r4 is 27 spline just like the th350. you dont need the adapter from the 208, you need the adapter from the 205 as well as the aftermarket spacer.
you will probably have to trim off a bit from the output shaft.

if you replace the output shaft in the trans you run into clearance problems with the front driveshaft rubbin on the trans pan.

the slip yoke will still work with your current driveshaft, i cant remember if its close enough in length or not. just add in a retube anyways into the budget.
 
73 was the first year of the 203 so alot of them are going to have 203s. look for a 72 they all had th350s mated to 205s if they had autos
 
this is what it will look like, this ones from an 80. the aluminum spacer is the techpak spacer.

DSC00015.jpg
 
blazinzuk said:
73 was the first year of the 203 so alot of them are going to have 203s. look for a 72 they all had th350s mated to 205s if they had autos
Click to expand...

I guess I have never really looked at a '73 K5, but all '73 K10's and K20's that have a TH350, have an NP205 from the factory as far as I know.

Martin
 
The brochure contradicts itself though, because it says on the second page that it has full time four wheel drive with automatic transmissions. Handy . . .

Martin
 
82355 said:
I guess I have never really looked at a '73 K5, but all '73 K10's and K20's that have a TH350, have an NP205 from the factory as far as I know.

Martin
Click to expand...

Not to start an arguement but I have seen about half and half in trucks (about a dozen that freind have had or I have looked at) 203 or 205 both cases came behind the th 350 in those years 73 is the only year I know of for sure though cause I have never had or looked at a 74 that has had an auto

I have only seen 203s in blazers
 
Okay, this is what I'm tracking:

  • The TH-350's 205 will have the 27-spline input to match the 700r4.
  • A TH-400's 205 will be 32-spline.
  • The 27-spline output is long output, so a spacer is required & possibly some additional shortening in order to keep it from bottoming out on the 205's input.
  • A 32-spline output shaft is shorter,therefore eliminating the need for the spacer, but that will in turn move the transfer case forward, causing the driveshaft interference condition to the 700r4 pan.

Correct?

82355 said:
ORD sells an output shaft for the TH700R4 to run an NP205 behind it, without using a spacer. Just another option (that requires disassembling the entire transmission).
h ttp://w ww.offroaddesign.com/catalog/trannyoutput.htm

Martin
Click to expand...

This output shaft allows the elimination of the spacer, but doesn't cause a front driveshaft interference to the 700r4?
 
yeah i swapped that over, the front half was more relevant than the rear i suppose.
 
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