69 GMC 1 ton dually. Convert to 4x4, HELP! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

truck1974 · 10-24-2004, 11:10 AM

Hi, I'm new to the board. I recently purchased a 69 GMC 1 ton dually. My friend told me the axle is a Eaton unit or something. I know it's not a 14 bolt or Dana 60. The motor is a straight 6, 292 I believe.
I was thinking of converting the truck to a 4x4. I was wondering how big of a job it would be to convert the front end over. Do you just remove the front A arms and hardware from the frame and find some spring shackles and springs and roll an axle under it or what? Are parts pretty easy to obtain and cheap for the conversion? Any input would be appreciated. By the way it has the 4spd with granny low. I was wondering what gears the rear might have. I can't find an ID tag and you'd have to pull the whole carrier to count the teeth. Thanks in advance.
Matt.

ryanroo · 10-24-2004, 11:52 AM

as far as the gear ratio goes, you can just jack up the rear axle and spin the driveshaft, count the number of times is spins for one revolution of the tires. little more than four, 4.10 four and a half, 4.56 ect. for the 4x4 conversion you would have to find a 4x4 frame and rob all of the sping hangars and enging crosmembers so you could use them for you frame. im pretty sure the frame is drilled for the spring hangars but i have no idea about the shackle mounts. good luck and welcome to the board
Ryan

**JIMs70GMC** · 10-24-2004, 01:38 PM

I've looked into doing this myself w/ a 72 1 ton I bought. The rear already has leaves, the front you'd need the front hangers and the shackle mounts from a donor. Board member Yukon Jack has a friend w/ a converted 1 ton. The 2wd 1 ton frame is different from the 2wd 3/4 and 1/2 ton frames as the frame does not bow out after the cab. In this regard they are the same as the 4x4 frames.

truck1974 · 10-24-2004, 04:16 PM

So would I need shackles, springs and hangers from the same vintage, 67-72 years, or could I use 73-87 parts also?

1969 GMC · 10-24-2004, 06:10 PM

if the 292 is stock, then you should have 4.57 gears in the Eaton, however 4.11s and 5.14s are also possible. It would be a good time to pull the centersection to see if you have a factory detroit locker, get the gear ratio, check the bearings, and change the gear oil which is most likely older than old.

**JIMs70GMC** · 10-24-2004, 07:14 PM

It would probably line up better using the 69-72 stuff, as the 73 and up springs are about 3" longer and would but the shackle further back on the frame and the axle would not be centered in the wheel well. When I get my 72 C30 i'm going to take some measurements between it and my 71 K20. Also the front spring hanger has the core support as part of it.

10-24-2004, 11:10 AM	#1
truck1974 Registered User Join Date: Oct 2004 Posts: 17	69 GMC 1 ton dually. Convert to 4x4, HELP! Hi, I'm new to the board. I recently purchased a 69 GMC 1 ton dually. My friend told me the axle is a Eaton unit or something. I know it's not a 14 bolt or Dana 60. The motor is a straight 6, 292 I believe. I was thinking of converting the truck to a 4x4. I was wondering how big of a job it would be to convert the front end over. Do you just remove the front A arms and hardware from the frame and find some spring shackles and springs and roll an axle under it or what? Are parts pretty easy to obtain and cheap for the conversion? Any input would be appreciated. By the way it has the 4spd with granny low. I was wondering what gears the rear might have. I can't find an ID tag and you'd have to pull the whole carrier to count the teeth. Thanks in advance. Matt.

10-24-2004, 11:52 AM	#2
ryanroo Senior Member Join Date: Apr 2004 Location: sw colorado Posts: 2,720	as far as the gear ratio goes, you can just jack up the rear axle and spin the driveshaft, count the number of times is spins for one revolution of the tires. little more than four, 4.10 four and a half, 4.56 ect. for the 4x4 conversion you would have to find a 4x4 frame and rob all of the sping hangars and enging crosmembers so you could use them for you frame. im pretty sure the frame is drilled for the spring hangars but i have no idea about the shackle mounts. good luck and welcome to the board Ryan __________________ 72 K20 12v build 72 K20 "parts truck" A place for your diesel swap questions

10-24-2004, 01:38 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I've looked into doing this myself w/ a 72 1 ton I bought. The rear already has leaves, the front you'd need the front hangers and the shackle mounts from a donor. Board member Yukon Jack has a friend w/ a converted 1 ton. The 2wd 1 ton frame is different from the 2wd 3/4 and 1/2 ton frames as the frame does not bow out after the cab. In this regard they are the same as the 4x4 frames. __________________ 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

10-24-2004, 06:10 PM	#5
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	if the 292 is stock, then you should have 4.57 gears in the Eaton, however 4.11s and 5.14s are also possible. It would be a good time to pull the centersection to see if you have a factory detroit locker, get the gear ratio, check the bearings, and change the gear oil which is most likely older than old. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

10-24-2004, 07:14 PM	#6
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	It would probably line up better using the 69-72 stuff, as the 73 and up springs are about 3" longer and would but the shackle further back on the frame and the axle would not be centered in the wheel well. When I get my 72 C30 i'm going to take some measurements between it and my 71 K20. Also the front spring hanger has the core support as part of it. __________________ 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

10-24-2004, 04:16 PM	#4
truck1974 Registered User Join Date: Oct 2004 Posts: 17	So would I need shackles, springs and hangers from the same vintage, 67-72 years, or could I use 73-87 parts also?



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