1978 K10 auto to 4 spd manual swap

[squaredeal91]

My main driver, a 1978 K10 I got years ago with a 350 and th350. I swapped in a 6.2L and a 700R4. Been wanting to manual swap for years now. Push has now come to a shove since the r4 died yesterday. (Lost 3rd and 4th) I'm pretty sure i have about all the pieces needed.
Im installing an SM465 from a 1984 k10 suburban. Using a 208 T-case. Im ordering transmission gasket set and input shaft bearing and painting trans. I should have everything except rear driveshaft. I might have one of those too possibly. Ill mostly have questions about clutch linkage.
I'm not trying to make it a how to but still hoping to help answer questions some may have and having enough pictures to go with.

 

[nvrenuf]

Are the 4spd and 208 a preexisting combo? If not, make sure they both have the correct spline counts to work together.

 

[squaredeal91]

Are the 4spd and 208 a preexisting combo? If not, make sure they both have the correct spline counts to work together.

yes they were. Trans and adapter is from a 1984 K10 suburban. Im using the t-case my truck currently has. Good point. Ill check splines soon. Ordering transmission gaskets today.

 

[nvrenuf]

But your existing 208 is paired with a 700r4, correct? That would make it a 27 spline unit and the '84 4spd would be 32 spline. The adapter would be correct but you'd have to swap the tcase input shaft for a 32 spline part.

 

[squaredeal91]

But your existing 208 is paired with a 700r4, correct? That would make it a 27 spline unit and the '84 4spd would be 32 spline. The adapter would be correct but you'd have to swap the tcase input shaft for a 32 spline part.

And your correct. I love this place lol. I just counted 32 spline. I must have a 241 then. Now I have to start digging for another transfer case. Here's some pictures of the trans and adapter

 

[squaredeal91]

it is a 208 C. Does the C mean something?
If this doesn't work I might have another. Maybe.

 

[legopnuematic]

C is for Chevrolet.
208s were also used in Dodge, Ford, and Jeep applications. suffix of D, F, and J.

 

[squaredeal91]

So the 208 i have can only be 27 spline? Or is there a chance that its a 32?

 

[squaredeal91]

C is for Chevrolet.
208s were also used in Dodge, Ford, and Jeep applications. suffix of D, F, and J.

Thank you for the refresher. I knew that once but totally forgot. Anyways, that 208 i have on my r4 is likely to be a 27 spline 208? Or is my R4 32 spline?

 

[nvrenuf]

So the 208 i have can only be 27 spline? Or is there a chance that its a 32?

If your 208 fit a 700r4, it can only be 27 spline.

The input shaft can be swapped.

Both 208’s and 241’s were available in 27 and 32 spline, input spline count is never an identifier for GM tcases.

 

[squaredeal91]

If your 208 fit a 700r4, it can only be 27 spline.

The input shaft can be swapped.

Both 208’s and 241’s were available in 27 and 32 spline, input spline count is never an identifier for GM tcases.

Thank you! Looks like I may need one of these unless I can find another way out.

 

[squaredeal91]

I ordered that 32 spline shaft . I also ordered transmission input shaft bearing, transmission gasket/seal kit and oil. Time to start cleaning parts up. Hopefully be starting in on it Saturday.
And thank you for the help. Not knowing about spline count difference would have set me back later on.

 

[squaredeal91]

Got my parts in. Remove seat to pull up carpet for making holes. Got transmission pretty clean and ready for paint. Removed old input shaft bearing. New bearing going in soon then gaskets.

 

[squaredeal91]

Last minute ordered this bearing from the number on the old one. Should be here in an hour. Does anyone know what this is called? As in what shaft rides on it. I already filled my work station lol

 

[squaredeal91]

Pulled up carpet and found some typical insulating material. However look at that round piece cutout. It looks to me to be the perfect shape for a 4 speed shifter hole? Was thinking of using this for my template only cutting 1-1/2 inch to the inside to begin with. Does that look right??