First, the NP203 questions :p
How difficult is it to find the TH400 version of the NP203 adapter? I know the input gear is still available. I know it was used in 78 and 79 3/4 and 1 ton GM pickups.

Is the TH400 input gear swapable with any NP203 case? I know the SM465, TH350, and Dodge input gears are swapable.

How difficult would it be to modify an TH350 adapter to mate a TH400 to NP203? I know with enough time, money, or expertise anything is possible:p


Now the NP205 questions
How durable are the TH350 input shafts(27 spline)?

How difficult is it to find a TH350 version of the NP205?

Yes, I searched... no I didn't find what I wanted :(

Thanks in advance,
John

Any 1980 auto equipped K series truck will have the NP205. '80 was a transition year, the 203 was discontinued in 79 and the 208 wasn't ready for production til 81 so all '80 models got the slip yoke 205. Most half ton '80 models should have had the TH350 version.

No clue on the 203 question...sorry.

Rene

Originally posted by Lil'John
First, the NP203 questions :p
How difficult is it to find the TH400 version of the NP203 adapter? I know the input gear is still available. I know it was used in 78 and 79 3/4 and 1 ton GM pickups.



Check on Ebay. They are on there quite a bit. That is where I got mine. For the TH350 version of the 205: 69(?)-72, There are a few 73's that had them( about 50% of the 73's that I have seen have had them), and 1980 w/the slip yoke.

Ok, in the order of your post...

The 400/203 adapter is pretty elusive. To begin with it was only used in 3/4 or 1 ton applications so that by itself makes it rare. The next bit of bad news is that those combo of parts are vital components of the ORD Doubler kit so they are getting REAL popular.

Sorry, I don't know about 3203 part interchangability.

You will not be able to modify the 350 adapter to fit a 400, the 350 has a square 4 bolt pattern and the 400 has an octagon 6 bolt pattern - the shape of the tranny side of the adapter is COMPLETELY DIFFERENT. The figure 8 pattern (previously referred to) on the tranny side is for 4spd's ONLY. Call Advance Adapters if you must use that part.

The weak part of the 350/205 design is most likely the coupler sleeve.

The 350 version of the 205 is realatively common since it was used in the 70's. Also, like tRusty said, ALL 80 model trucks came with a 205.

Originally posted by nvrenuf
Ok, in the order of your post...

The 400/203 adapter is pretty elusive. To begin with it was only used in 3/4 or 1 ton applications so that by itself makes it rare. The next bit of bad news is that those combo of parts are vital components of the ORD Doubler kit so they are getting REAL popular.

Actually, the only thing that is now "popular" due to ORD Doubler kit is the 32 spline NP205(five) due to the "large" hole.

I haven't seen an increase of people saying "I've got a TH400 to NP203 to NP205" on the board :p

Thanks for the rest of the info... quite helpful:D

I think the 10 spline 203 is pretty popular as well since the intro of the ORD doubler

and at only $60 IIRC to bore the 205 case for the big bearing they are no big deal

Exactly. And while the TH400/NP203s are more common than for the 465, they are still much more in demand (and therefore more $$$) due to the doubler... :( A few years ago, you could barely GIVE away a 203, especially the odd balls from a 465 or 400...

3 weeks ago I picked up a good TH 400 and 203 out of the wrecker for $ 350.00 :D