The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > All 4x4 Tech & Off Roading

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 02-12-2005, 10:18 AM   #1
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
help with year of K20 chassis

I have a 3/4 ton 4x4 chassis under a 71 GMC 4x2 body. I am not sure of the year of the chassis, it has disc brakes, hub size for rims are 4 3/4" (see pictures), and the front leafs are 3" wide.
Attached Images
  

Last edited by Tully; 02-12-2005 at 12:45 PM.
Tully is offline   Reply With Quote
Old 02-12-2005, 12:55 PM   #2
Mudder
Registered User
 
Mudder's Avatar
 
Join Date: Feb 2001
Location: East Central, MO
Posts: 11,336
Sounds like a newer frame like mine but those that really know will help ya out.
Mudder is offline   Reply With Quote
Old 02-12-2005, 01:33 PM   #3
Mudder
Registered User
 
Mudder's Avatar
 
Join Date: Feb 2001
Location: East Central, MO
Posts: 11,336
Ok Tulley after giving you crap over on the other board for douple posting hehe, few questions about your frame. Does it have a sway bar? Are there extra holes where the cab mounts? I have a 77 chassis and it has 3 inch wide springs.
Mudder is offline   Reply With Quote
Old 02-12-2005, 02:25 PM   #4
Rod
 
Join Date: Dec 1999
Location: Eastern - Manitoba Canada, Winnipeg
Posts: 4,369
3inch wide leafs I believe are 73 up.
__________________
Senior active founding member.
70 3/4 ton GMC Suburban 4x4 250/4 spd.
71 1/2 ton Suburban Chevy 4x4, 350/350
72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane
2005 FLSTSCI Harley Springer
85 FXSB Harley Lowrider
72 Triumph 650 Bonneville 5spd
"Poor people don't have hobbies" Quote from wife.
Rod is offline   Reply With Quote
Old 02-12-2005, 04:50 PM   #5
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
Mudder, there are no extra holes in the frame but I have come to the conclusion that the PO put 73 up front springs under it. The brackets and shackles are bolted on. The rear shock and spring mounts are riveted on so they didn't try shortening a 73 up chassis. I started sanding through the caked rust to try and find the frame number I will let you know what I find.
Tully is offline   Reply With Quote
Old 02-12-2005, 05:50 PM   #6
Blazer1970
Registered User
 
Blazer1970's Avatar
 
Join Date: Dec 1999
Location: Old Mission, MI, USA
Posts: 2,510
Get the BOM number off the front Dana 44. It will tell you the original year and application.
__________________
Tim
Blazer1970 is offline   Reply With Quote
Old 02-12-2005, 08:15 PM   #7
JIMs70GMC
user # 2756
 
JIMs70GMC's Avatar
 
Join Date: Jun 2001
Location: Chesapeake, Virginia
Posts: 4,612
Are the leaves 3" over the whole length of the spring? Stock for my 70 and 71 were 3" wide at each end and 2.5" in the center. 2nd, on the 3/4 tons I believe the internal style hub showed up in 76 or 77, before that they were all external style. Measure the length of the front springs, 73 and up springs are 3" longer than the 72 and earlier springs.
__________________
1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs
1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX
1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears
1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now.....
1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone.
1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed.

1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm
JIMs70GMC is offline   Reply With Quote
Old 02-12-2005, 09:14 PM   #8
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
Tim, the numbers I found on the dana 44 are C-31256 287 44 5F
Jim, you are right the springs are 3'' at both ends and 21/2" in the middle. I never noticed that before. With weight on it they measure 43 3/4", hole center to hole center.
Tully is offline   Reply With Quote
Old 02-13-2005, 05:05 PM   #9
Blazer1970
Registered User
 
Blazer1970's Avatar
 
Join Date: Dec 1999
Location: Old Mission, MI, USA
Posts: 2,510
Quote:
Originally Posted by Tully
Tim, the numbers I found on the dana 44 are C-31256 287 44 5F
Jim, you are right the springs are 3'' at both ends and 21/2" in the middle. I never noticed that before. With weight on it they measure 43 3/4", hole center to hole center.
The BOM number is a 6 digit number that will be stamped on the front of the axle tube to the right of the pumpkin when looking under the front of the truck. You will likely have to sand some rust off the tube to reveal the numbers.
__________________
Tim
Blazer1970 is offline   Reply With Quote
Old 02-13-2005, 07:52 PM   #10
JIMs70GMC
user # 2756
 
JIMs70GMC's Avatar
 
Join Date: Jun 2001
Location: Chesapeake, Virginia
Posts: 4,612
Tully, those are pre 73 springs. Same length as both my trucks. 73 and up are 46" long. I say your axle is a late 70s and your frame is pre 73 maybe even a converted 2wd truck.
__________________
1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs
1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX
1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears
1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now.....
1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone.
1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed.

1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm
JIMs70GMC is offline   Reply With Quote
Old 02-13-2005, 08:55 PM   #11
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
Tim, I sanded down and found 10 20 1A4 603351 3

Jim, I think you just nailed it. Its a 2wd body and they put the front differential under it, that's why it's bolted. To do this they had to lift the truck because of the low hump. ( I put a high hump in and dropped it back down). The only other thing that puzzles me is the large rims needed. The only rims I have found are Ford, chrysler and some white spokes that will fit. In fact the chrysler ones only work up front.
Tully is offline   Reply With Quote
Old 02-13-2005, 09:41 PM   #12
1969 GMC
Registered User
 
1969 GMC's Avatar
 
Join Date: Feb 2003
Location: The Rubber City
Posts: 5,498
603351
DANA 44 FRONT
Year 1972
Make CHEVY
Model K5 Blazer, K10 1/2 Ton Pickup & Suburban & Panel Truck
Number of axle splines: 30 FULL


hope it helps!
__________________
1969 GMC K2500
1996 Honda Accord
2007 Kawasaki KLR 650
1969 GMC is offline   Reply With Quote
Old 02-15-2005, 12:34 PM   #13
poff
Registered User
 
Join Date: Dec 1999
Location: san diego, ca
Posts: 546
The VIN number should be stamped in the frame somewhere.
__________________
'70 K-20 San Diego, CA
poff is offline   Reply With Quote
Old 02-15-2005, 09:09 PM   #14
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
I looked for the Vin # on top of the frame rail by the power steering pump and nothing there. Where else should I look?
Tully is offline   Reply With Quote
Old 02-16-2005, 08:54 PM   #15
Rod
 
Join Date: Dec 1999
Location: Eastern - Manitoba Canada, Winnipeg
Posts: 4,369
Its under the cab also....but can't really be seen without removing the cab.


If" 1969 GMC "found info on dating your front axle..it could be that some one just swapped out the locking hub style to newer version locking hubs, and the hub its self. It can be done and might of had to have been done that way as parts for the 70-72 style 3/4 ton locking hubs are hard to find.
__________________
Senior active founding member.
70 3/4 ton GMC Suburban 4x4 250/4 spd.
71 1/2 ton Suburban Chevy 4x4, 350/350
72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane
2005 FLSTSCI Harley Springer
85 FXSB Harley Lowrider
72 Triumph 650 Bonneville 5spd
"Poor people don't have hobbies" Quote from wife.
Rod is offline   Reply With Quote
Old 02-16-2005, 10:02 PM   #16
DennyB
Led Sled! Discs R 4 ME!
 
DennyB's Avatar
 
Join Date: Jan 2001
Location: Toms River, NJ, USA (Transplanted Hoosier)
Posts: 7,327
If its a converted 2wd chassis, a hole would have to be drilled in the frame for the rear shackle to mount (on the front diff.)

Here.........
Attached Images
 
__________________
"Never ride faster than your Angel can fly"
I.M.O.M,W,J&C
Patriot Guard Rider
DennyB is offline   Reply With Quote
Old 02-18-2005, 09:56 AM   #17
Tully
Registered User
 
Join Date: Jan 2005
Location: Hiles, WI
Posts: 42
Denny, yes it looks like the rear shackles were added, they cobbled some steel plates on the outside of the frame that covers up the hole they cut.
Tully is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:31 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com