1978 K10 Manual to TH350 Conversion

[alradco]

Hello,
A few months ago I bought a 78 4x4 stepside to work on with my younger son. This is now his daily driver since he turned 16 recently. So far we've just made sure it's mechanically sound and installed HID lights (what an improvement)  Here's a pic of the truck.



The truck has a 4 speed manual but we'd like to convert it to a TH350. I've searched and haven't been able to find too much info on what needs to be done. The truck has a 350 and NP205 transfer case. If anyone has some input or can point me in the right direction it would be appreciated. Thanks in advance.

[Jason S]

Nice K-10!   Welcome to the site!

Is there a particular reason for wanting to swap for an automatic transmission? 

You might consider finding a donor truck and get all the needed parts.    Adapting your current t-case to the TH350 can be done, but it may be a bit pricey. Then there's modifying driveshafts and adding in for the transmission cooling, swapping columns, etc. 

There are quite a few threads on swapping out a SM-465 for a TH350, TH400 or 700R4; as well as swaps the other direction.  Have you tried a search on this forum?   

Here are a few examples:

http://forum.73-87chevytrucks.com/smforum/index.php?topic=29608.0

http://forum.73-87chevytrucks.com/smforum/index.php?topic=29466.msg246489#msg246489

http://forum.73-87chevytrucks.com/smforum/index.php?topic=24679.msg205856#msg205856

http://forum.73-87chevytrucks.com/smforum/index.php?topic=17735.msg141220#msg141220

http://forum.73-87chevytrucks.com/smforum/index.php?topic=17179.msg136033;topicseen#msg136033

http://forum.73-87chevytrucks.com/smforum/index.php?topic=7059.msg40480#msg40480

[alradco]

Thanks for the links Jason. I've searched and read as many threads as I could find, still learning my way around here. 
As far as why the conversion, the current 465 is having a tough time going through gears, pops out of gear, grinds, and overall is just not fun to drive especially if you get into any traffic. Though instead of doing a rebuild might just convert it to TH350 or TH400 if it's not too big of a project. Thanks again.