Need Help Identifying 4x4 Puzzle truck!

[jugadro]

OK,
So I have a Black 1970 K20 4X4 with a 402 BBC and a TH350 (I think).

I need to buy some stuff for the truck; U-joints, brakes, diff gaskets, etc. However, the VIN# decodes it as a 1970 2wd step-side, and it's making it difficult to get correct parts. I'm also trying to figure out what I have for axles, and eventually gears.
I did find a number stamped on the frame by the power steering pump - 0J125115.
I've tried looking for identification help but couldn't find much of anything.

Judging by illustrations in LMC catalogs, I'm wondering if it is sitting on a '73-87 frame? This is beginning to drive me .

I'll have photos of the underside soon, until then any knowledge would be greatly appreciated. Thanks.

[jugadro]

OK, here are some pics of my truck...
Sorry about their hugeness!

Front end;


Rear end;

Transfer case (NP?);

[CUSTOM/10]

From the pic's I would say it probably is a 70 3/4 ton frame. The previous owner probably changed the cab at some time hence the #s not matching. The front end is a dana 44, and the rear is an eaton. It looks like the ID tag is still on the front diff. ( Tag is under the lower left hand bolt of the front diff cover ) This tag will tell you your gear ratio. Other board members will most likely have additional input for you.

Gary

[bouncytruck]

The transfer case looks like a NP205 to me. NP203's look similar, but the 205 has the small cover with the three bolts.

Here is a link to an axle guide.
http://coloradok5.com/axleguide.shtml

[jugadro]

Originally Posted by bouncytruck

Here is a link to an axle guide.
http://coloradok5.com/axleguide.shtml

Thanks! - that is one handy link!

[drink2mny]

I definately will agree with the above guys...
205 transfercase
Dana 44 basically 73-up frontend
Eaton third member- 72- down

[jugadro]

I also thought it was a '70 3/4 ton until I tried to buy U-joints and brakes. Did later models have this same axle setup?

I sure would be happy if it was a 70, but the steering setup looked like a '73+ based on LMC catalog illustrations.

[XLR8N]

i found out that 67-72 front springs are 42'' from eye to eye and 73-77 springs are 47'' eye to eye. i ordered a lift kit and it did not fit-found out i had a 73 frame. frame was also stamped below the dr door with a build date. hope it helps

[XLR8N]

p.s. the rear looks pre 73 due to square u-bolts that bolt from the bottom and rear shocks are not staggered. later model trucks had rounded u bolts that bolt on top and one shock mounts front and one shock mounts rear on the axle. thats all i got

[CUSTOM/10]

The frame it's self appears to be 67-72 due to the cab mounting to it correctly. If it was a later modle frame the frame cab mounts would have to have been modified and they look stock.

Later modle trucks also had dana 44 front ends, but they changed the rear ends ( I believe in 73 ) to corperate 14 bolt. You could take your old brake pads & axle joint to the parts store and have then match them up.

Gary

[Beast388]

I'll agree with what the other have said. It looks like the chassis is original with the exception of the front axle. It is a Dana 44, but appears to be a 1977-79 version. The giveaway is the non-flat top knuckles and the fact that the tie-rod mounts from the underside of the knuckles. The 1976 and older D44's had tie-rods that mount from the top down.

When buying brakes, the rotors, pads and calipers are interchangeable from 71-79 on the 8-lug D44's.

You should be able to find the BOM (bill of materials) number on the front of the driver's side axle tube. Then go here to find all the info about the axle.

[Hoods69BadBowTie]

Yeah, that is a 205 transfer case. 67-72 frame maybe?
Bouncy thanx for posting that axle id webpage.
-Later

[Rod]

Everything I can see here leads to a 1970 3/4 ton 4x4 frame and suspension.

The front diff has had at least the outside locking hubs changed.....it appears to be disc brake and 1970 had an open dana 44 front with drum brakes..making it the only year that could be changed to disc up front by changing backing plates outward. So someone either changed the brake system to disc on the outside of the diff or swapped in a newer dana 44 that being a 71- about 78 era dana 44 front. A pic of the hubs would be more clues to what year vintage the outside for the disc brake system is. Beast388 may be right on the dana 44 77-79 era..I never noticed which way the tie rod went..my 1970 have them top down...it also has flat top knuckles...in my 70 drum brake dana 44..so I'd say 1970 is the starting year of flat top.

From what you posted of the frame stamped vin its a 1970 frame built in Janesville.
Simple enough if you know what your looking at.

The transfer case is part time NP 205 ,..correct for year also and has correct style outputs from what I see.
The rear is a eaton/ corp 10 bolt style diff cover..also correct. I'd say proabby 4.57 gears ..the front tag on the front dana 44 (which it is) will more give you a ratio close to that..they werent exactly same ratio...off by a bit for handling and steering. Regardles its 4.10 or 4.57..no other choices practically. I'd bet on 4.57 in 1970.

Just looking at what I see like fan shrouds and brackets I recognize...its a 70. I'd probably know. I dream this stuff sometimes.

[jugadro]

Wow, so I may not be up the creek as far as I thought I was. I was worried that getting parts was going to be a nightmare. It seems as though the diagrams in the LMC parts catalog may not be entirely accurate or correct. Or perhaps they just failed to show all of the different setups that were built.

Do any of you recommend any other part catalogs / sources for these old beasts. I'm fairly new at having a truck this old and so far I've only dealt with LMC.

Thanks for all of the help - I'm gonna go buy some brakes - And take some hub pictures while I'm at it - And maybe replace the U-joints while I have it apart.

[geunther]

I have found the lmc and other books get a little sloppy. Especially as far as what pictures they show with part numbers. It makes it confusing becuase I have ordered what I know to be the correct part # but the picture is something completely different.

Cross member under oil pan also strongly suggests pre 73 frame. Not sure about axle itself but lack of factory mount for steering stabalizer (hole in tie rod) indicateds pre 73 for that part. not sure of exact year that was introduced but know it was after 72.

Agree with others posts also, np205 etc.

[jugadro]

OK, I just finished my brakes and here's what I have found so far (albeit accurate or not):

Both axles have 8-lug hubs.

FRONT AXLE
Tag numbers:
45-11
4.09
Stamped numbers:
3
C-31256
44-5P

Springs - about 43-44" eye to eye

I ordered brake pads for a '77 3/4 ton and they worked great.

REAR AXLE
Tag:
none
Stamped Numbers:
3934635
(then a wagon wheel looking thingie)
D

I ordered brake shoes for a '70 P30 with 12" drums (2" wide shoes) and they were identical to what was on it. We spent extensive time looking in the thick reference guide at the auto parts store and he believes the rear axle is that of a '46-'70 P-series 1 ton.

I'm getting there... slowly.

Thanks for all your help!

[72longbed]

Thats an HO72 Rear. As far as I can tell from the pics, the front axle is a 'flat top' D44. Pics taken closer to the upper ball joint area would help more.

Looks good.

72longbed

[special-K]

When do we get pictures of this Bast....er mutt?That`s not such a mutt after all.

[jugadro]

Originally Posted by special-K

When do we get pictures of this Bast....er mutt?That`s not such a mutt after all.

Well here is a pic taken last year. Unfortunately the winter salt is beginning it's destructive cancerous toll on the truck. I'm seeing little bubbles multiplying like wet gremlins.

Too bad they don't make a POR15 truck dip...
Or maybe I'll spray the entire truck with Rhino Linings - heheh.

[El Dorado Jim]

Originally Posted by jugadro

Well here is a pic taken last year. Unfortunately the winter salt is beginning it's destructive cancerous toll on the truck. I'm seeing little bubbles multiplying like wet gremlins.

Too bad they don't make a POR15 truck dip...
Or maybe I'll spray the entire truck with Rhino Linings - heheh.

Beautifultruck!!!!

[18436572GMC]

I agree with everyone else on what you have. A 67-72 frame due to the fact that the body mounts line up, np-205 t case, dana 44 front, eaton ho-52 or ho-72 (ho-72 has load bolt on side of housing) I did see a sign not mentioned that your axle has been changed. look at how far the u bolts stick up past the nuts, they are longer than factory u bolts.
As for a rear disc brake conversion I use ruff stuff specialties 14 bolt brackets. You will need to use 72 front calipers pads and rotors, and drill out the wheel stud holes to fit 9/16th studs. I used wheel studs for a 1995 f250. 72 front brake lines will work to connect to hard lines. I run this with no proportioning valve and it does great.
didn't mean to make that so long.

[18436572GMC]

also since im an ill add that the last year for eaton rear ends was 72 as the 14 bolt came out in 73
It might just be your pic but it looks like your front drivers side u bolts are missing a nut. Don't want you to walk an axle off its perch.

[Stocker]

Originally Posted by swamp rat

My understandig is that both HO-52 and HO-72 could have the load bolt, the main difference was the use of 11" shoes or 13" shoes

Yup, HO72 had larger brakes, most likely because it was on 1-ton trucks, and the 3/4 tons got the HO52.

As to the load bolt, some HO52s had it and some did not.... but all HO72s had it.

[Yukon Jack]

It's a great looking truck.

[budbeater]

The back axle is a Eaton HO52. I believe the HO72 was a one ton and/or dually model. The gearing for the Eaton was 4.10, 4.56 or 5.13. You might want to start saving $$$ for a disk conversion for the rear or a 14 bolt swap since the 12" drum parts (drums and wheel cylinders) are unavaliable for the Eaton anymore. The good thing is that the Eaton is a full float axle and the axle shafts are wicked tough.

Budbeater