np205 compatability

[the_goat]

Would an np205 from a 77 4 speed chevy be the same as my 205 in my 70 blazer? How much should I pay for one in good working condition. I'm planning on rebuilding mine but can't afford the down time on my truck so I'm looking for a cheap one to rebuild.
Thanks for the help

[the_goat]

I did a search that listed 2 different 205s from 71-85, one with 10 splines and one with 27 splines, for a 4 speed and th350 respectively. Now I'm not sure which I have. Stock it was behind a th350 but has the stock adapter.
I appreciate it.

[hdflstf]

I don't know the exact years and differences. I think the 77 will have the different splines and adapter bolt pattern.

Take a look on craigslist, you should be able to find an NP205 from a similar year truck without too much trouble.

[FormerMember]

What trans do you have in your K5?

[CDA 455]

Originally Posted by the_goat

Would an np205 from a 77 4 speed chevy be the same as my 205 in my 70 blazer? How much should I pay for one in good working condition. I'm planning on rebuilding mine but can't afford the down time on my truck so I'm looking for a cheap one to rebuild.
Thanks for the help

Two things come to mind:

1) Mount surface (Race track or round) between engine and adaptor.

2) Spline count (ten, twenty-seven, or thirty-two).


Race track mounting surface was on early models; round came on late models.

Ten spline: early; twenty-seven spline: middle; thirty-two spline late.

[the_goat]

The 77 205 is a 10 spline and looks identical to mine but I haven't removed mine to look at the output shaft.

[CDA 455]

Originally Posted by the_goat

The 77 205 is a 10 spline and looks identical to mine but I haven't removed mine to look at the output shaft.

I think the ten spline came with a 465 attached to it.

[the_goat]

Thanks guys, I'll start looking for a 27 spline 205 then. Just curious did the next gen trucks use the same adapter between the th350 and 205 as well? I was getting hung up on the word "adapter" thinking it was a 10 spline with an adapter to run with a th350.

[FormerMember]

Originally Posted by the_goat

Thanks guys, I'll start looking for a 27 spline 205 then. Just curious did the next gen trucks use the same adapter between the th350 and 205 as well? I was getting hung up on the word "adapter" thinking it was a 10 spline with an adapter to run with a th350.

Yes, they did. The "Figure 8" adapter was used until mid 80's. Most of the 4 speed 205s will be 10 spline MALE input (they require a goofy female to female coupler). Mid 80's they (4 speed 205's) switched to 32 spline.

I have a Figure 8 205 here, with 27spline female input. I was going to use it on my build but went with a 32 spline instead.