![]() |
|
![]() |
#1 |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
1977 K20 Trannys
Any of you 'old timers' out there remember what automatic transmission came with the 1977 3/4 ton 400 cu.in. Chevy 4x4 pickup trucks with the NP205 Full time four wheeldrive. I want to settle an argument with a friend, he said you could get a THM 400 with that truck. I remember the THM 350 was the only tranny that came with full time fourwheel drive, no matter what . What say you guys?
|
![]() |
![]() |
![]() |
#2 |
5 day ban, learn to behave.
Join Date: Nov 2002
Location: san diego, ca
Posts: 684
|
If it is the NP205, its a part time truck.. The NP203 was fulltime and would have been a TH350 trans behind it, in 1977.... In other years you could get a th400 and in '74 you could even get a SM465 3spd manual on the full time 4x4...
Bottom line is that it is possible to find/build a full-time (np203) with a th400, they are uncommon though... as for 1977 strictly, I dont think you could have gotten a th400/np203 combo because Ive never seen or heard of one.. But thats not fact. I think I have some brochures somewhere, or you could look at that one brochures site that grim reaper always posts.. mike |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
Thanks Mike, I know my memory is a little fuzzy after 26yrs. I thought full time 4wheel drive was the NP205. But I do remember that I could not order the THM 400 in that truck, I went to several different Dealers. My friend insists he had one in his '77.
Thanks again. |
![]() |
![]() |
![]() |
#4 |
5 day ban, learn to behave.
Join Date: Nov 2002
Location: san diego, ca
Posts: 684
|
another thing that popped into my head since you mentioned special ordering, was I went to look at a parts truck at this guys house and the truck was a '78 K20 that the guy special ordered from the factory, with a th400 and full time 4x4... The truck was in parts and he told me it was a th400.. looking thru the shed, I saw the t-case and knew it was a NP203, and so I say "are you SURE its a th400?" he says yes, he had to special order it.. I looked at the T-case adapter and sure enough it had the 6-bolt hexagonal pattern. So the general MADE em but I dont think they mass produced em for the normal dealer shipments.
On a side note, that setup is actually quite desireable to some parts seekers because the NP203+th400 adapter can be used to build a dual transfer case setup that would bolt to a TH400...... a TH400+NP203gearbox+NP205 would be about as bulletproof as you could get... enough rambling.. hope this enlightened you some mike |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Apr 2003
Location: New Mexico. Of all places for an Island boy.
Posts: 180
|
In 77 with a 400cid engine the trany is a TH-400, For sure my Bonanza came that way!
|
![]() |
![]() |
![]() |
#6 | |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
Quote:
|
|
![]() |
![]() |
![]() |
#7 | |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
Quote:
![]() |
|
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Apr 2003
Location: New Mexico. Of all places for an Island boy.
Posts: 180
|
The Bonanza is/was a special promotional package. I checked Chuck's Chevy Trucks and in 77 all 400/454 engine'd trucks came with a 4-core radiator and a TH-400 tranny.
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Apr 2003
Location: New Mexico. Of all places for an Island boy.
Posts: 180
|
Oh yeah...my 77 came with a np-203 tc too.
|
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Nov 2003
Location: Grants PassOregon
Posts: 335
|
My 77 originally had a 400 an 203/TH400....course, Im the third owner, an when I got it someone had swapped the Th400 for a TH350.....an the 400 SB for a 350.....so, as far as I know...it came with TH400 and NP203....
__________________
The Devil ![]() 1983 ONE TON 454/400/208 11" of lift on 44's |
![]() |
![]() |
![]() |
#11 | |
5 day ban, learn to behave.
Join Date: Nov 2002
Location: san diego, ca
Posts: 684
|
Quote:
that is definately incorrect. my 77 K25 gmc was 400sb/th350/np203 mike |
|
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Apr 2003
Location: New Mexico. Of all places for an Island boy.
Posts: 180
|
Perhaps, Mike, perhaps.
|
![]() |
![]() |
![]() |
#13 |
5 day ban, learn to behave.
Join Date: Nov 2002
Location: san diego, ca
Posts: 684
|
I think that different areas (geographically) will see major differences in what GM put out.. Especially being that Im in california.. I dont doubt for a minute that they made th400 full timers.. but I do know that in the several years Ive been into the 73-87 4x4s, (mainly 77), ive never seen a th400/np203 truck.. and ive seen a LOT of trucks.. with the exception of the '78 parts truck in my previous post. That, coupled with the fact that I have seen many (including my own unmolested) 77 th350/np203 K25, brings me to the conclusion that yes you get a th350 OR th400 full time 3/4ton pickup thru the years.. one may be more common than the other (depending on location?) but they were both available. were they both available in 77? maybe. in fact- probably. Is it unreasonable to say that you could ONLY get a th400/np203 in 1977? Yes =)
mike |
![]() |
![]() |
![]() |
#14 |
Account Suspended
Join Date: Oct 2002
Location: Elkhart, IN
Posts: 6,400
|
my uncle has a 79 K20 with a TH400/203 in it, and my grandpa had a 77 K20 with a TH350/205
|
![]() |
![]() |
![]() |
#15 |
Registered User
Join Date: Apr 2003
Location: New Mexico. Of all places for an Island boy.
Posts: 180
|
Hey for enough $$$ GM could sell you a special order truck with GM electric diesel power. Look at all the CPO"S and the "muscle" cars of the 60's. I have found that not much is written in stone.
|
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
Well I was reading through ChucksChevytrucks pages, and it said the Th350 was the only tranny available from '73 to '76. And the th400 were 'available' from '77 & later. So that means that 1977 was a transition year and possably early 1977's had the th350's & later models had th400's if you chose to order so. When buying my 1977 I decided to go with the 2wd for two reasons. Nicer ride and I wanted the 454/TH400 combo, wich I know for sure did not come in the 4x4's. I would have settled for the 400SB/TH400 in the 4x4 but was told it was not available, this was in Jan. of 1977. BTW, I still have this truck, it's all original. I stored it every winter. See signature.
|
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Oct 2002
Location: LAS VEGAS, NV.
Posts: 157
|
400-203
got a 74 blazer with turbo 400 and 203 tc. it isn't a full removable top either. thought both were strange.
__________________
troy wilson |
![]() |
![]() |
![]() |
#18 | |
Account Suspended
Join Date: Oct 2002
Location: Elkhart, IN
Posts: 6,400
|
Quote:
|
|
![]() |
![]() |
![]() |
#19 |
Registered User
Join Date: Nov 2003
Location: Crabwell Corners
Posts: 9
|
[QUOTE]Originally posted by 1FaastC10
[B] consider your source. not very reliable information at all, as far as i can tell. Yes, I agree as I noticed other discrepancies while reading through chuckscchevytrucks. |
![]() |
![]() |
![]() |
Bookmarks |
|
|