Click on image for the lowdown. 
====
| | | Forums66 Topics128,187 Posts1,057,212 Members48,465 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Oct 2012 Posts: 22 New Guy | | New Guy Joined: Oct 2012 Posts: 22 | We pulled the Engine, Transmission and Transfer out of the 1977 today. Got so busy and forgot to take progress pictures. I used the pulp loader to remove it all and it was quite the chore and a good day.
Question??? - The Transfer is a 203 and the front Axles which are ?Dana 4:56? with full time hubs. In a past post someone identified that the 203 with a conversion would be a good choice. I'm searching now to find out as much information about this 203 Transfer and whether it is a full time transfer or whether it shifts to 2wd. I used this truck for years but don't remember the details.
The 1977 K20 sat since 1993 and we started the engine before pulling it. After having to change the Starter because the solenoid was shot, it started right up and ran like a charm. We could not believe how well it ran with no problems what so ever, just none and it was very impressive. So we are going to use the 350, Auto and 203 transfer in the 1964 K20.
It was a great day.
| | | | | Joined: Oct 2012 Posts: 22 New Guy | | New Guy Joined: Oct 2012 Posts: 22 | I found the Information I guess.
Mile Marker may be the best choice for the transfer case conversion to be able to select 2wd high, 2wd low, 4wd high 4wd low
and there is a good description on the directions on how to make the change.
What are my best choices to change over to the locking/ unlocking hubs?
| | | | | Joined: Apr 2006 Posts: 78 Shop Shark | | Shop Shark Joined: Apr 2006 Posts: 78 |
"The Marines I have seen around the world have the cleanest bodies, the filthiest minds, the highest morale, and the lowest morals of any group of animals I have ever seen. Thank God for the United States Marine Corps!"
Elanor Roosevelt
1966 c-10 stepside
1966 c-10 fleetside
1964 c-10 fleetside
1964 c-10 short bed
1964 c-30 flat bed
1964 c-60 dump truck
1968 Impala
1969 Nova
1971 Nova
1975 LUV
1976 C-30
1977 K-20
1966 SS El Camino
| | | | | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | Your best bet would be to put the 203 back to full time operation. Just about every part time conversion I've ever dealt with on the 203 never really worked right. If you would prefer a part time system, swap to the 205 gear drive t-case. For extra low end grunt, there are kits out there that will allow you use the 203 range box with the 205 t-case, giving you a compound low range.
Bill Burmeister
| | | | | Joined: Apr 2006 Posts: 78 Shop Shark | | Shop Shark Joined: Apr 2006 Posts: 78 | I agree with Mr.Longbox. The 203 transfer case is bullet proof stock. Fuel milage is the only reason to convert to part time. I've done the conversion and undone the conversion. You don't have to get out and lock the hubs;It's already there.
"The Marines I have seen around the world have the cleanest bodies, the filthiest minds, the highest morale, and the lowest morals of any group of animals I have ever seen. Thank God for the United States Marine Corps!"
Elanor Roosevelt
1966 c-10 stepside
1966 c-10 fleetside
1964 c-10 fleetside
1964 c-10 short bed
1964 c-30 flat bed
1964 c-60 dump truck
1968 Impala
1969 Nova
1971 Nova
1975 LUV
1976 C-30
1977 K-20
1966 SS El Camino
| | | | | Joined: Aug 2009 Posts: 12 New Guy | | New Guy Joined: Aug 2009 Posts: 12 | The 203's are ok T-case's, but if depends on what you are going to do with it. I have put a part time kit in one and never had any trouble with it, but I wouldn't use a 203 unless I had no other choice. The chains are really bad to stretch and brake, any serious off road use go with a 205 all gears in them, but a 208 is a tough T-case and it has a lower low range than any of them.Just my 2 cents hope everything works out Axe | | | | | Joined: Jul 2008 Posts: 413 Shop Shark | | Shop Shark Joined: Jul 2008 Posts: 413 | I have a 205 out of a 1980, it was bolted to a TH350. I was saving it for my 86, but I dont see that happening.
The 205's are bullet proof, no chain to break, & they have the cover on the side for a PTO which is kind of nice.
I also have a 208 out of an 86.
Last edited by JeffL; 05/18/2014 12:53 PM.
| | | | | Joined: Apr 2010 Posts: 436 'Bolter | | 'Bolter Joined: Apr 2010 Posts: 436 | The 203's are ok T-case's, but if depends on what you are going to do with it. I have put a part time kit in one and never had any trouble with it, but I wouldn't use a 203 unless I had no other choice. The chains are really bad to stretch and brake, any serious off road use go with a 205 all gears in them, but a 208 is a tough T-case and it has a lower low range than any of them.Just my 2 cents hope everything works out Axe I had a 350/TH350/NP203 setup in my 1977 Blazer. The previous owner had done the part time conversion on it. It was fine, but I agree the 203's have a weak link (pun intended) in the Chain Drive. I broke it a couple of times. I ran the Rubicon in that truck. Of course, I wouldn't do that again, full size trucks are just too big for that route. | | |
|
|
