2wd to 4wd - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Beefcake · 04-08-2003, 09:31 AM

Hey guys,

Im sure im not the first to ask this question, Im sorry if Im repeating it. I own a 72' Fleetside. Its a great truck, buuuuuutttt...

It would be nice if I could have 4wd instead of 2wd. Im currious if anyone has done it before, wheather Im headed for a nightmare.

Is just a simple swap of suspentions and transfercase/ front diffential???

Or is there something im missing, such as 4x4's have a wider frame.

Oh... and One more question.... I was wondering whats the best vehicle to grab my parts from.... Can I get into the 73+ vehicles??? are they better/ more durable???

Thanks much!!

**JIMs70GMC** · 04-08-2003, 01:36 PM

I've thought of this my self, to take a 3/4 or 1 ton truck(69-72) and convert it to 4wd. I've never really compared the frames but I believe the areas of concern would be: Front spring hanger is offset to the out board side of the frame, front shackle end at frame is directly under frame, tranny cross member and transfercase mount on pass side frame. I believe all 4wds are high hump and would need to have transfer case hole. Engine would have to be mounted in back position. Oh yea probably better to use a truck that already has rear springs. Everything I mentioned is centered around using all GM stuff, with little as possible fabrication(drilling for front hanger, etc..).

Beefcake · 04-08-2003, 02:13 PM

Ya, I've got a bone yard hear with plenty of pickens..... I dont know prices yet, but the idea looks very attactive.....

jabarlow · 04-08-2003, 03:31 PM

IF YOU CAN FIND A 4-WHEEL DRIVE FRAME THAT WOULD WORK BEST OTHERWISE I WOULD RECOMMEND MAKING SYRE THAT YOU HAVE ONE AT LEAST CLOSE BUY TO COMPARE THE DIMENSIONS TO MY 72 ONLY HAS ONE SET OF HOLES TO MOUNT THE ENGINE CROSSMEMBER TO AND THE FRONT BRAKE LINES ARE DIFFERENT

1969 GMC · 04-08-2003, 03:34 PM

I think I'd stick with 67-72 stuff if making a 2wd into a 4wd if possible. The only concession I might make is to use a Dana 60 front axle out of a K30, but if you don't do alot of offroading, a Dana 44 from a 67-72 would be ok. But a Dana 60/Eaton combo would be a hard combo to beat.

**JIMs70GMC** · 04-09-2003, 05:38 AM

Something else to think about: why convert a truck that came in both 2wd and 4wd, i.e. 1/2 and 3/4 ton. Why not find a longhorn or cab and chassis truck? Also I believe the 3/4 and 1 ton frames are similar to the 4wd drive frames. Imagine 133" or longer wheelbase dually cab and chassis 4wd. You could swap in a dually dana 60 up front (easier to find and cheaper) and out back would already be a dually eaton.

02hook · 04-10-2003, 07:33 AM

I am wanting to do the same thing with my 71 chevy truck. Let's tag team the research and share info!

What do ya say?

Sorry guys, I forgot to scoll down and see that all of you had already replied to beefcake.

I apologize fior the wasted reply!

Beefcake · 04-10-2003, 09:06 AM

I did notice that someone on this site had a dana 44 for only 75 bucks in texas.....

Id buy that in a second if I didnt have to ship it here.

**JIMs70GMC** · 04-10-2003, 11:12 AM

Something else: steering boxes are different.

Beefcake · 04-10-2003, 12:34 PM

Im thinking about junking the 3 speed and upgrading to a 3/4 ton 4 speed......

are the 4x4 4 speeds any diffrent???

red450ih · 04-10-2003, 01:10 PM

If y'all have a coil rear in your trucks, I would recomend finding a 4WD frame and swap cabs/beds. The coil rear frames go from 34" to 38" back to 34" in the rear. That makes them alittle harder to work with.

Keith

Beefcake · 04-10-2003, 01:47 PM

Thanks keith! thats the kinda stuff I was worried about. I've got leafs.... anybody else??

**JIMs70GMC** · 04-10-2003, 04:22 PM

The 4 speeds should be the same: SM465

Longhorn4x4 · 04-13-2003, 12:50 PM

Been there, done that.

IF you have a leaf spring rear frame, it isn't a HUGE deal.

You can buy the front hangers for the front springs new from GM for a 73-87, they'll nearly bolt right on.

You REALLY need to find the 67-72 shackle mounts for the rear of the front springs. The later model shackle hangers DO NOT fit well, and they do not work well either.

I just changed the Pitman arm on the steering box.

On the rear, I used the spring hangers off of a late model truck, they were also a near bolt on.

I used the front crossmember from a 70 K5 Blazer. It bolted in.

I have TWO transmission/transfer case crossmembers from a late model, they also were a near bolt in. I'm using two because I'm installing a 203/205 doubler.

Make sure you get ALL of the brackets and braces. Get all the pieces for the crossmembers too.

Make sure you get aircraft style and quality grade 8 bolts, with AN hardened washers, and use aircraft quality nylock type nuts and jam nuts. The smooth shank of the bolt should be long enough to extend through both the frame and the bracket or brace, because threads are NOT strong enough when in shear. I also bought some 5/16" dowel pins, the case hardened type, and used a drill to drill through the brackets and the frame, two per bracket, to locate the brackets tightly. Remember that the original brackets are RIVETED on, and rivets are tighter and stronger than your average bolt of the same size.

I made a plate to reinforce the frame behind the steering box.

I avoided welding the brackets on, despite the fact that I have both a MIG and a TIG welder and the ability to use them well. The problem with welding on the old frames is that you can easily screw up the heat treat of the frame and bracket causing a weak spot.

The truck I started with happens to be a 1970 Longhorn my Dad bought brand new, that's why I converted it rather than bought another truck. I wanted a Longhorn 4x4.

Others may well disagree with my methods. I'm very picky about stuff. I'm using all premium urethane mounts on my engine and transmission/transfer case besides those cab to frame mounts. I also used the late model style engine mount to dust cover strut rods, the strut rod from the side of the transfer case to the bellhousing, and the side mount that goes between the transfer case and the frame. I like a stiff frame because I HATE broke stuff, especially stuff like frames and bellhousings. I run BIG big block Chevy engines with plenty of power, and I use a truck hard.

Good luck to you,

Longhorn 4x4

**JIMs70GMC** · 04-14-2003, 05:22 AM

You got some pics of that longhorn? I myself would like to convert a dually cab and chassis w/ a longer wheelbase.

02hook · 04-17-2003, 06:10 AM

I see many different transfer cases out there. Which is the model that I am looking for to put in a 1970 Chevy 3/4 ton with a Big Block engine? Also, if I jump on a dana 44 front axle, is there a special case that effects this end also?

Longhorn4x4 · 04-21-2003, 07:42 PM

Quote:

Originally posted by 02hook
I see many different transfer cases out there. Which is the model that I am looking for to put in a 1970 Chevy 3/4 ton with a Big Block engine? Also, if I jump on a dana 44 front axle, is there a special case that effects this end also?

There's really only one good transfer case for a 4X4 that really gets used. The New Process 205. It fits most GM transmissions both auto and manual. The 400 is the best automatic (unless you have the money for a 4L80E), the SM 465 is the cheapest and most reliable manual.

The Dana 44 is a decent axle, I prefer the older models with the large genuine Dana Spice external hubs (use Loctite to keep the hubs tight). For a big block powered truck I'd go with a Dana 60, even thought it is twice the price. Fixing frontends, especially on the trail, is a PITA.

By the way, for those who asked, there are no pictures of my truck, yet.

pancho · 04-29-2003, 08:08 PM

There was an article talking about a 69 or 70 blazer that was originally 2wd and had been converted to 4wd. The front suspension was that of a ford, with a straight axle, and radius arms (like the 78 and newer fords not to be confused with TTB).

This was featured as a rock crawler, since the articulation was absolutely nuts (the rear trailing arms on the 2wd can give phenomenal travel).

Anyways, I am unable to locate this article. Has anyone seen it? It's circa 1999 or 2000, perhaps 2001 in Peterson's Four Wheeler, or maybe in 4wd & suv. I forget where I read it but it said something like "Stretchy" or something.

I ask because I'd like to do this to a blazer as well, using the ford front coil suspension with pro-comp long radius arms. I'd do it for comfort, mostly and just to be able to go fast through bumpy stuff in the desert.

Any responses will be greatly appreciated.

Thanks.

04-08-2003, 09:31 AM	#1
Beefcake Registered User Join Date: Mar 2003 Location: Motor City Posts: 540	2wd to 4wd Hey guys, Im sure im not the first to ask this question, Im sorry if Im repeating it. I own a 72' Fleetside. Its a great truck, buuuuuutttt... It would be nice if I could have 4wd instead of 2wd. Im currious if anyone has done it before, wheather Im headed for a nightmare. Is just a simple swap of suspentions and transfercase/ front diffential??? Or is there something im missing, such as 4x4's have a wider frame. Oh... and One more question.... I was wondering whats the best vehicle to grab my parts from.... Can I get into the 73+ vehicles??? are they better/ more durable??? Thanks much!! __________________ 72 GMC Camper Special 2500. currently has 350/350/14 bolt. 383 and 400 tranny is in the works. Last edited by Beefcake; 04-08-2003 at 09:54 AM.

04-08-2003, 01:36 PM	#2
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I've thought of this my self, to take a 3/4 or 1 ton truck(69-72) and convert it to 4wd. I've never really compared the frames but I believe the areas of concern would be: Front spring hanger is offset to the out board side of the frame, front shackle end at frame is directly under frame, tranny cross member and transfercase mount on pass side frame. I believe all 4wds are high hump and would need to have transfer case hole. Engine would have to be mounted in back position. Oh yea probably better to use a truck that already has rear springs. Everything I mentioned is centered around using all GM stuff, with little as possible fabrication(drilling for front hanger, etc..). __________________ 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

04-08-2003, 02:13 PM	#3
Beefcake Registered User Join Date: Mar 2003 Location: Motor City Posts: 540	Ya, I've got a bone yard hear with plenty of pickens..... I dont know prices yet, but the idea looks very attactive..... __________________ 72 GMC Camper Special 2500. currently has 350/350/14 bolt. 383 and 400 tranny is in the works.

04-08-2003, 03:31 PM	#4
jabarlow Registered User Join Date: Dec 2002 Location: DENVER, CO Posts: 90	IF YOU CAN FIND A 4-WHEEL DRIVE FRAME THAT WOULD WORK BEST OTHERWISE I WOULD RECOMMEND MAKING SYRE THAT YOU HAVE ONE AT LEAST CLOSE BUY TO COMPARE THE DIMENSIONS TO MY 72 ONLY HAS ONE SET OF HOLES TO MOUNT THE ENGINE CROSSMEMBER TO AND THE FRONT BRAKE LINES ARE DIFFERENT __________________ 72 Chevy K10 Short Stepside 72 gmc K2500

04-08-2003, 03:34 PM	#5
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	I think I'd stick with 67-72 stuff if making a 2wd into a 4wd if possible. The only concession I might make is to use a Dana 60 front axle out of a K30, but if you don't do alot of offroading, a Dana 44 from a 67-72 would be ok. But a Dana 60/Eaton combo would be a hard combo to beat. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

04-09-2003, 05:38 AM	#6
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Something else to think about: why convert a truck that came in both 2wd and 4wd, i.e. 1/2 and 3/4 ton. Why not find a longhorn or cab and chassis truck? Also I believe the 3/4 and 1 ton frames are similar to the 4wd drive frames. Imagine 133" or longer wheelbase dually cab and chassis 4wd. You could swap in a dually dana 60 up front (easier to find and cheaper) and out back would already be a dually eaton. __________________ 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

04-10-2003, 07:33 AM	#7
02hook Registered User Join Date: Apr 2003 Location: Jacksonville, FL Posts: 2	ditto beefcake I am wanting to do the same thing with my 71 chevy truck. Let's tag team the research and share info! What do ya say? Sorry guys, I forgot to scoll down and see that all of you had already replied to beefcake. I apologize fior the wasted reply! Last edited by 02hook; 04-10-2003 at 07:44 AM.

04-10-2003, 09:06 AM	#8
Beefcake Registered User Join Date: Mar 2003 Location: Motor City Posts: 540	dana 44 I did notice that someone on this site had a dana 44 for only 75 bucks in texas..... Id buy that in a second if I didnt have to ship it here. __________________ 72 GMC Camper Special 2500. currently has 350/350/14 bolt. 383 and 400 tranny is in the works.

04-10-2003, 11:12 AM	#9
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Something else: steering boxes are different. __________________ 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

04-10-2003, 12:34 PM	#10
Beefcake Registered User Join Date: Mar 2003 Location: Motor City Posts: 540	3/4 ton 4 speed Im thinking about junking the 3 speed and upgrading to a 3/4 ton 4 speed...... are the 4x4 4 speeds any diffrent??? __________________ 72 GMC Camper Special 2500. currently has 350/350/14 bolt. 383 and 400 tranny is in the works.

04-10-2003, 01:10 PM	#11
red450ih Registered User Join Date: Mar 2001 Location: Nashville, Tennessee Posts: 225	If y'all have a coil rear in your trucks, I would recomend finding a 4WD frame and swap cabs/beds. The coil rear frames go from 34" to 38" back to 34" in the rear. That makes them alittle harder to work with. Keith __________________ GMC

04-10-2003, 01:47 PM	#12
Beefcake Registered User Join Date: Mar 2003 Location: Motor City Posts: 540	4x4 ??? Thanks keith! thats the kinda stuff I was worried about. I've got leafs.... anybody else?? __________________ 72 GMC Camper Special 2500. currently has 350/350/14 bolt. 383 and 400 tranny is in the works.

04-10-2003, 04:22 PM	#13
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	The 4 speeds should be the same: SM465 __________________ 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

04-13-2003, 12:50 PM	#14
Longhorn4x4 Registered User Join Date: Oct 2002 Location: Murfreesboro Tennessee Posts: 58	converting from 4x2 to 4x4 Been there, done that. IF you have a leaf spring rear frame, it isn't a HUGE deal. You can buy the front hangers for the front springs new from GM for a 73-87, they'll nearly bolt right on. You REALLY need to find the 67-72 shackle mounts for the rear of the front springs. The later model shackle hangers DO NOT fit well, and they do not work well either. I just changed the Pitman arm on the steering box. On the rear, I used the spring hangers off of a late model truck, they were also a near bolt on. I used the front crossmember from a 70 K5 Blazer. It bolted in. I have TWO transmission/transfer case crossmembers from a late model, they also were a near bolt in. I'm using two because I'm installing a 203/205 doubler. Make sure you get ALL of the brackets and braces. Get all the pieces for the crossmembers too. Make sure you get aircraft style and quality grade 8 bolts, with AN hardened washers, and use aircraft quality nylock type nuts and jam nuts. The smooth shank of the bolt should be long enough to extend through both the frame and the bracket or brace, because threads are NOT strong enough when in shear. I also bought some 5/16" dowel pins, the case hardened type, and used a drill to drill through the brackets and the frame, two per bracket, to locate the brackets tightly. Remember that the original brackets are RIVETED on, and rivets are tighter and stronger than your average bolt of the same size. I made a plate to reinforce the frame behind the steering box. I avoided welding the brackets on, despite the fact that I have both a MIG and a TIG welder and the ability to use them well. The problem with welding on the old frames is that you can easily screw up the heat treat of the frame and bracket causing a weak spot. The truck I started with happens to be a 1970 Longhorn my Dad bought brand new, that's why I converted it rather than bought another truck. I wanted a Longhorn 4x4. Others may well disagree with my methods. I'm very picky about stuff. I'm using all premium urethane mounts on my engine and transmission/transfer case besides those cab to frame mounts. I also used the late model style engine mount to dust cover strut rods, the strut rod from the side of the transfer case to the bellhousing, and the side mount that goes between the transfer case and the frame. I like a stiff frame because I HATE broke stuff, especially stuff like frames and bellhousings. I run BIG big block Chevy engines with plenty of power, and I use a truck hard. Good luck to you, Longhorn 4x4

04-14-2003, 05:22 AM	#15
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	You got some pics of that longhorn? I myself would like to convert a dually cab and chassis w/ a longer wheelbase. __________________ 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



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04-17-2003, 06:10 AM	#16
02hook Registered User Join Date: Apr 2003 Location: Jacksonville, FL Posts: 2	transfer cases I see many different transfer cases out there. Which is the model that I am looking for to put in a 1970 Chevy 3/4 ton with a Big Block engine? Also, if I jump on a dana 44 front axle, is there a special case that effects this end also?

04-29-2003, 08:08 PM	#18
pancho Registered User Join Date: Apr 2003 Location: San Diego, CA Posts: 1	2wd to 4wd conversion There was an article talking about a 69 or 70 blazer that was originally 2wd and had been converted to 4wd. The front suspension was that of a ford, with a straight axle, and radius arms (like the 78 and newer fords not to be confused with TTB). This was featured as a rock crawler, since the articulation was absolutely nuts (the rear trailing arms on the 2wd can give phenomenal travel). Anyways, I am unable to locate this article. Has anyone seen it? It's circa 1999 or 2000, perhaps 2001 in Peterson's Four Wheeler, or maybe in 4wd & suv. I forget where I read it but it said something like "Stretchy" or something. I ask because I'd like to do this to a blazer as well, using the ford front coil suspension with pro-comp long radius arms. I'd do it for comfort, mostly and just to be able to go fast through bumpy stuff in the desert. Any responses will be greatly appreciated. Thanks.

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