[Mark1968]

I`m looking at one to replace my dakota the neighbor back into to. This one`s 3/4 ton 35/400 auto, with a dana 60 in the rear and dual tanks. I know it has full time 4 wheel.

I`m sure someone has experience with these, anything to watch out for? And is there a website for these trucks like py is for pontiacs?

[Txbobcat]

You need to watch out for gas stations as the 3/4 ton and the full time 4 wheel drive isnt going to pass to many of them up.

[sleepy]

It doesn't have duel tanks for nothing. I wouldn't get a full time 4WD unless you spend ALL of your time off road in the swamp.

[BILTIT]

You can convert to part-time 4wd for ~150 bucks or change T-cases.

http://www.summitracing.com/parts/SPW-900802/



One of the largest sites dedicated to 69-91 k5, suburban, pickups.

www.coloradok5.com

I have an '80 3/4T camper special with 350/400/14 bolt.

[stimpy]

its a tank ( and fuel wise ..) I had a 3/4 ton camper special withthe same setup, if you get the kit to make the transfercase Part time and change to manual locking front hubs , and ru the tire pressure at maximum you can squeeze 10-12 Mpg out of it , I used to hang a peice of converyor belt off the front bump er( hang it with fix it links for chain ) the full width ( and 6" off the ground ) to break the Air Drag around the front axle assy and got 15 Mpg ( w/4:56 gears and 16.5 D X 10 w tires ( cant rememer the height I think they where 32"s . if you put headers on it and a Dual 2.5 exaust to the back with Flowmasters you can increase your power and milage . the things to look out for are bed cross over rot outs ( the top of the bed looks fine but the cross member is rotted ) you ussually don'y find this out till you put a engine in the bed and it falls thru , buy a extra fuel tank selector valve and keep itiin the truck , and extra fuses ( found out the brake lights are also connected to the tank selector switch and when the fuse pops the valve dont work . ) when you work on the front axle replace all the u-joints at that time and buy good ones !! its easier to buy a new front drive shaft with the the double yoke than to rebuild it !
Keep the jack in truck instead of on the front wheelhouse as it has a tendency to undo and fall out ( ussualyy 40 miles from where your tire will blow out !or fall out and blow out the rear tire when it gets crushed ) BUY good coated headers !! and check the oil pan for rust outs they are known to rust from the inside out ! and Have fun with it ...

[Me Notyou]

Also check out the frame near the steering box, they like to crack a bit as I discovered with my 76 4wd 4spd K5. Check out the rear floor and the rear wheelwells. Also if the truck has a swing out tire carrier mounted on the rear make sure to look for cracks or rust where it is mounted. That transfercase should be an NP203. Very strong VERY heavy unit. Good if converted over to a part time. If you do replace the T-case go with an NP205. Is this truck a blazer or a pickup?

[BILTIT]

Yup, if the frame is cracked around the steering box there are weld-in and bolt-in repair/support kits, i have both to prevent cracking.

Also check the draglink from the steering box to the steering arm, usually very worn out and most causes of sloppy steering.

[Mark1968]

Thanks for the advice. The truck is a c/d longbed. The only plan is to change the front hubs to part time, repair some rust and drive the wheeee out of it.

[mike nixon]

FWIW the diff isn't a dana 60 in the rear unless it's an oddball. It'll be a 14 bolt corprate which is stronger than the Dana 60.

MY 78's had several powertrains in it. The current one is a 6.2 diesel with a pump that's turned up to the ragged edge of being a coal burner a 4spd manual trans, 4:10's and 33"'s. It pulls 22 mpg on a regular basis, 13 pulling 13k lbs against the govenor.

I'l agree on the t/case conversion, it's the best move you'll ever make for fuel economy and drivability. A good set of headers and a free flowing exhaust will gain you 1-2 mpg. In stock form mine ran 13 with a 350 / turbo 400 / 4:10's 33" tires. Lockouts and headers got it up to 16 during warm weather with a 350 that dyno'd out at 479 ftlbs of torque @ 2900rpm.

These are some of the best trucks GM ever built.

Mike

[Keith Seymore]

Yes -

http://67-72chevytrucks.com

There is a specific message board for 73-87 pickups.

K

[Mark1968]

Originally Posted by mike nixon

FWIW the diff isn't a dana 60 in the rear unless it's an oddball. It'll be a 14 bolt corprate which is stronger than the Dana 60.

MY 78's had several powertrains in it. The current one is a 6.2 diesel with a pump that's turned up to the ragged edge of being a coal burner a 4spd manual trans, 4:10's and 33"'s. It pulls 22 mpg on a regular basis, 13 pulling 13k lbs against the govenor.

I'l agree on the t/case conversion, it's the best move you'll ever make for fuel economy and drivability. A good set of headers and a free flowing exhaust will gain you 1-2 mpg. In stock form mine ran 13 with a 350 / turbo 400 / 4:10's 33" tires. Lockouts and headers got it up to 16 during warm weather with a 350 that dyno'd out at 479 ftlbs of torque @ 2900rpm.

These are some of the best trucks GM ever built.

Mike

RE the rear end, the center section pulls out from the front side as opposed to the back, like a 10 or 12 bolt. I was assuming.

[BILTIT]

Sounds like an old eaton which the 14bolt replaced or else someone put a ford 9'' in it.

Does it look like this from behind?

(Scroll down)

http://www.pirate4x4.com/forum/showthread.php?t=771317

If so then it is an eaton HO52 (3/4ton) or HO72 (1 ton).

[Formulabruce]

Originally Posted by BILTIT

Sounds like an old eaton which the 14bolt replaced or else someone put a ford 9'' in it.

Does it look like this from behind?

(Scroll down)

http://www.pirate4x4.com/forum/showthread.php?t=771317

If so then it is an eaton HO52 (3/4ton) or HO72 (1 ton).

Nah, its an 8 lug FULL FLOATER, used to be called an "ambulance rear end" If you break it the axles dont fall out on a corner. Probably is a dana, dont think the corporate ones were like that, but GONICGM is My resident expert on that stuff.
I bet it still has a 205 unit, not a 203.
Its got 411 for 4wd, and the 2 wd drive used 410 gears, go figure...
the posis have a govenor that breaks, Im sure theres a workaround for it, if its got one.
seems the guys here have a handle on what goes bad, and rusts.
Its a damn rugged truck if you dont off road much, putting a ROAD tire thats E rated on it and one size bigger will help your mileage some.

[mike nixon]

Originally Posted by Mark1968

RE the rear end, the center section pulls out from the front side as opposed to the back, like a 10 or 12 bolt. I was assuming.

At some point that's been changed. As mentioned above It's probably an Eaton unit unless someone had a custom unit made.


MIke

[BILTIT]

Originally Posted by Formulabruce

Nah, its an 8 lug FULL FLOATER, used to be called an "ambulance rear end" If you break it the axles dont fall out on a corner. Probably is a dana, dont think the corporate ones were like that, but GONICGM is My resident expert on that stuff.
I bet it still has a 205 unit, not a 203.
Its got 411 for 4wd, and the 2 wd drive used 410 gears, go figure...
the posis have a govenor that breaks, Im sure theres a workaround for it, if its got one.
seems the guys here have a handle on what goes bad, and rusts.
Its a damn rugged truck if you dont off road much, putting a ROAD tire thats E rated on it and one size bigger will help your mileage some.

Full floaters were made in both 14 bolt and dana 60 flavours. They were used on heavy 3/4T and 1T applications.

The NP203 was used in trucks with auto trans to '79, the 205 was used with manuals until '80 when all models received the 205.

If there is a gov-lok in it and its a 14bolt then they are plenty strong. They are however very weak in the 10-12 bolts.

73-80 K10 had 4.11's, K20-30's had 4.10's.

[mike nixon]

Originally Posted by BILTIT

Full floaters were made in both 14 bolt and dana 60 flavours. They were used on heavy 3/4T and 1T applications.

The NP203 was used in trucks with auto trans to '79, the 205 was used with manuals until '80 when all models received the 205.

If there is a gov-lok in it and its a 14bolt then they are plenty strong. They are however very weak in the 10-12 bolts.

203's were also used in stick shift full time apps. They're pretty rare but are out there.

Mike

[BILTIT]

Yup, there are oddballs for sure.

[stimpy]

Originally Posted by BILTIT

Full floaters were made in both 14 bolt and dana 60 flavours. They were used on heavy 3/4T and 1T applications.

The NP203 was used in trucks with auto trans to '79, the 205 was used with manuals until '80 when all models received the 205.

If there is a gov-lok in it and its a 14bolt then they are plenty strong. They are however very weak in the 10-12 bolts.

73-80 K10 had 4.11's, K20-30's had 4.10's.

Just don't get the wheels spinning if you get stuck because if it grabs its going to explode the carrier on the drivers side ( on my 3rd one , have pictures of the carrnage .... ) they are thin on the drivers side of the carrier unit . if its open get a detroit locker and put it in there . as for the eatons where discontinued in the 77 models on the C/K series and then they went to the 14 bolt with a dana 60 option ( which didin't last long ) , easiest way to identiy the 14 bolt is the removable pinion unit the whole pinion carrier comes out the front ) , the dana has to come out the back , and the Np 205 Iron case was a option on the 3/4 -1 ton with auto trans , standard with the contractor /camper special mdels and theres a 3rd t-case avail for the 1 ton that ha a Pto drive option . 203 /205 still strong units . and leave the torque rods that connect the engine to the trans on to keep from cracking bell housing ! and always check the adjustment on the rear brakes ( every oil change ) as the 13" brakes are known for not self adjusting as the front brakes will stop it adiquitly and the front pads will wear out fast ! ( 30 K miles ) ( rear brakes will last 80-120K miles )

if you take care of it ( and wash the underside of the body regularly ) you can have the truck a long time , my last one before the exwife got it had 275,000 miles on it . my 96 is just breaking in at 130K , also cjheck to see if your motor had the cam changed out as that was the last year of the imfamous flat cam recall .

[BILTIT]

I think most 203/205's had the pto option, atleast all of mine have.

[mike nixon]

Originally Posted by BILTIT

I think most 203/205's had the pto option, atleast all of mine have.

Every one I've owned, and that's been a LOT, Have had PTO provisons also.

MIke