3/4 ton to dually conversion - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Duallie · 10-08-2004, 02:30 AM

Dunno about duallie drums, but I DO know about duallie discs.
There are two sizes of rotors. Both are 12.5" in diameter. The thickness is the difference. The "lighter" and earlier style uses a spindle exactly like the same-era 3/4 ton spindle, and the rotor is the same 1.25" thickness. The calipers are the same as 3/4 ton, too.
All GM duallie rotors I have seen were one piece, with the spacer cast in and not even a place to machine and drill for studs if you were to cut off the "spacer."
The larger rotors are 1.5" thick, one piece, the calipers are completely different and the spindles are larger and have the caliper mount cast in, instead of bolted on. The calipers slide on the iron instead of pins. The caliper slides remind me of Ford caliper slides on trucks of the same era.
I found my first set of the big brakes on a '76 crewcab 2wd chevy with "camper special 10,000gvw" emblems on the cab.

Brainchild · 10-08-2004, 09:13 AM

In 73 they converted to the big lug wheels,which is a good thing.
The wheels off of the 67 1 ton we have won't fit any of the other trucks because of the lug diameter.

Also on the front drum/rotor,the surface the wheel mates to is moved to the outside.I mean that the wheel bearing doesn't stick out like it does on a 1/2 3/4 ton tuck,it's recessed almost.I'm not sure if that will stop you from using the spindles.

There are adapter plates to bolt the duallie wheels on the rearends.We have a 3/4 ton with duallies on the back using the adapter plates.

**JIMs70GMC** · 10-08-2004, 09:17 AM

When you say lug diameter or you talking the bolt circle? hub center diameter? or wheel stud size? I thought they were all 8 on 6.5". With the 40+ series bigger than that.

Robert1970C20rstbukt · 10-08-2004, 04:09 PM

He's talking about the wheel stud's diameter, like it's 1/2 or 9/16 of an inch in diameter. Ya know, the thing that the lug nuts go on.

**JIMs70GMC** · 10-08-2004, 06:50 PM

So what's considered big? My 70 has 1/2" studs and my 71 has 9/16" studs? Did they even go bigger?

Robert1970C20rstbukt · 10-08-2004, 09:26 PM

They went to 9/16" studs in 71, 67-70 had the 1/2" studs. 9/16" was the biggest that were on regular light duty pickups, the 40 up series had some pretty big ones, don't remember exactly how big, I think they were like 5/8" or something like that.

**67sss** · 10-08-2004, 09:58 PM

Well either I'm blind,ignorent,dumb or all of them, so I'll ask the question...Why not just take a 1T dually rearend and put it on a 3/4t. Are they diff..? hard to find? need one? 7000# or A 11,000#..?

Tx Firefighter · 10-08-2004, 10:00 PM

Quote:

Originally Posted by 67sss

Well either I'm blind,ignorent,dumb or all of them, so I'll ask the question...Why not just take a 1T dually rearend and put it on a 3/4t. Are they diff..? hard to find? need one? 7000# or A 11,000#..?

Because I already have a 3/4 ton truck. I want to put a welding bed on it and dual the wheels out to have a dually. Plus, it's got 4.10 ratio, which is better than a lot of the duallys I see, which have 4.56 or 5.13 or whatever deep ratios.

Tx Firefighter · 10-08-2004, 10:15 PM

Look, here's what started the whole thing.

This little truck was for sale by my house. I got to looking at it, and it was a C-20 truck with normal 3/4 ton type front wheels, but a dually rear.

So, I looked under it, and sure enough, it was a converted 3/4 ton. It had coil springs in the rear. All duallys were leaf spring from the factory, so obviously this was a conversion job.

Awhile back, I got a good deal on a 3/4 ton longbed 72 truck. I want to put a bed on it like this little red truck has, convert the rear to dual, AND convert the front to a proper dually, so the wheels match all around.

It looks to me, like with the right wheels and studs, the rear is possible. I mean, the pictures can't lie right?

In the front, it would seem that the rotors from a dually will swap onto my 72 3/4 ton disc spindles.

I need a set of wheels and a set of front rotors now.

*1972C10* · 10-08-2004, 10:20 PM

Try to get an old booster truck They have some pretty nifty flatbeds/pto setups on them

**67sss** · 10-08-2004, 10:20 PM

so finding a 4:10 dually 1 t rearend must be next to impossible? are the letter/number codes the same on a rearend off a 1/2t,3/4t vs 1t?

**67sss** · 10-08-2004, 10:23 PM

gotch ya. above post was done B4 I saw your pics.

Tx Firefighter · 10-08-2004, 10:28 PM

Quote:

Originally Posted by 67sss

gotch ya. above post was done B4 I saw your pics.

Nah man, I wasn't trying to sound....trying....It's just that I have looked at a couple of duallys and they usually have impossibly low gears in the rear end.

Plus, I want to build a short dually like the little red one. It has the same wheelbase as a normal longed truck. Most duallys I find are old cab and chassis trucks with the same wheelbase as a Santa Fe freight train. Like 150 something inches rather than 120 something inches.

Plus, I have this little 4.10 geared 3/4 ton truck just sitting in my field. I'm only into it for 200 bucks.

I have found places that sell brand new dually wheels for 80 bucks each. I figure for a thousand, I can get new wheels and tires. A little some of this and some of that, build a bed, and I'll have my little truck I want for way less than buying one.

mcmlxix · 10-08-2004, 10:38 PM

This is what I picked up on tuesday. It started out as a RV Camper, but water damage over the years had the camper roof sagging. I forgot to take a before pic. This is the after, 3 days later. You can still see the majority of the rubble in the back ground ... Glove box reads 157" wheel base ... an "RO5" for "DR WHEEL CONVERSION" ...

mcmlxix · 10-08-2004, 10:39 PM

Hey TX... I just bought a C30 Dually camper. I am taking the drive train and cab. I will end up with a 1 ton rolling chassis for sale.I think the glove box read 157" wheel base .... but I dont remember and its dark out! Its also optioned for dual rear wheels but I dont know the ratio...
If you or anyone is interested, PM me. It's in Las Vegas (north of the city)
Looking for $800.
I will also have some "Custom/30 DELUXE" badges, Dark Green Deluxe door pannels in really nice shape with great chrome trim and other misc small parts... but I dont want to turn this into a "parts for sale" thread ...so I'll stop here ...

longhorn71 · 10-08-2004, 10:47 PM

Quote:

Originally Posted by Robert1970C20rstbukt

Yep, those studs and the lugs are way bigger that the ones on my truck. The drum almost looks the same though.

Longhorn71,

OK, I saw that blue 1 ton truck that you told me about. If you have both spacers hold on to 'em for me. EDIT: And if the jr west coast mirrors on that truck are in good shape I'd be interested in a set.

No problem,Robert. I am not sure on the mirrors but i now the brackets are in nice shape

Robert1970C20rstbukt · 10-08-2004, 10:55 PM

OK, thanks man. PM sent.

BLAZERMAN · 10-08-2004, 11:11 PM

You guys might want to check out this truck on Ebay, lots of good pics on a dually conversion.

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

*1972C10* · 10-08-2004, 11:16 PM

Cab And Chassis Rearend

Tx Firefighter · 10-08-2004, 11:45 PM

All 67-72 duallys were cab and chassis trucks.

**JIMs70GMC** · 10-09-2004, 05:11 AM

Another option if it came down to it, you don't say what type of 4.10 rear you have, but if it's an eaton and the duallys of the era were eatons then the centers should swap. The catch 2wd rear spring(1/2, 3/4) spacing is wider than the (1 ton) spring spacing which I believe is the same as the 4wd rear spring spacing.

*rage'nrat638* · 10-09-2004, 07:28 AM

Yea I Would Like To Make My C-20 Into Duals In The Rear.....

can I....can I....can I....

*1972C10* · 10-09-2004, 09:14 AM

Quote:

Originally Posted by Tx Firefighter

All 67-72 duallys were cab and chassis trucks.

Its a conversion though.

**JIMs70GMC** · 10-09-2004, 08:15 PM

Here's the 72 I'm getting:

and the rear axle

Robert1970C20rstbukt · 10-09-2004, 09:05 PM

Dude that truck looks cool with the step bed on it!

10-08-2004, 02:30 AM	#26
Duallie Registered User Join Date: Feb 2001 Location: Nikiski, Alaska Posts: 477	Dunno about duallie drums, but I DO know about duallie discs. There are two sizes of rotors. Both are 12.5" in diameter. The thickness is the difference. The "lighter" and earlier style uses a spindle exactly like the same-era 3/4 ton spindle, and the rotor is the same 1.25" thickness. The calipers are the same as 3/4 ton, too. All GM duallie rotors I have seen were one piece, with the spacer cast in and not even a place to machine and drill for studs if you were to cut off the "spacer." The larger rotors are 1.5" thick, one piece, the calipers are completely different and the spindles are larger and have the caliper mount cast in, instead of bolted on. The calipers slide on the iron instead of pins. The caliper slides remind me of Ford caliper slides on trucks of the same era. I found my first set of the big brakes on a '76 crewcab 2wd chevy with "camper special 10,000gvw" emblems on the cab. __________________ Just as if I knew what I was doin'

10-08-2004, 09:13 AM	#27
Brainchild Still drivin' a Rat Rod Join Date: Sep 2004 Location: Monett Missouri Posts: 4,925	In 73 they converted to the big lug wheels,which is a good thing. The wheels off of the 67 1 ton we have won't fit any of the other trucks because of the lug diameter. Also on the front drum/rotor,the surface the wheel mates to is moved to the outside.I mean that the wheel bearing doesn't stick out like it does on a 1/2 3/4 ton tuck,it's recessed almost.I'm not sure if that will stop you from using the spindles. There are adapter plates to bolt the duallie wheels on the rearends.We have a 3/4 ton with duallies on the back using the adapter plates. __________________ Rusty Member #13872 Instead of saying.....you are a discomfort in the back of my front.....one should be able to say...... you are a pain in the a$# 71 GMC LWB 49 Chevy 85 Chevy G20 Check out my website

10-08-2004, 09:17 AM	#28
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	When you say lug diameter or you talking the bolt circle? hub center diameter? or wheel stud size? I thought they were all 8 on 6.5". With the 40+ series bigger than that. __________________ 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

10-08-2004, 04:09 PM	#29
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	He's talking about the wheel stud's diameter, like it's 1/2 or 9/16 of an inch in diameter. Ya know, the thing that the lug nuts go on. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

10-08-2004, 06:50 PM	#30
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	So what's considered big? My 70 has 1/2" studs and my 71 has 9/16" studs? Did they even go bigger? __________________ 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

10-08-2004, 09:26 PM	#31
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	They went to 9/16" studs in 71, 67-70 had the 1/2" studs. 9/16" was the biggest that were on regular light duty pickups, the 40 up series had some pretty big ones, don't remember exactly how big, I think they were like 5/8" or something like that. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

10-08-2004, 09:58 PM	#32
67sss Registered User Join Date: Nov 2002 Location: Mt. Vernon, WA.. Posts: 2,322	rearend Well either I'm blind,ignorent,dumb or all of them, so I'll ask the question...Why not just take a 1T dually rearend and put it on a 3/4t. Are they diff..? hard to find? need one? 7000# or A 11,000#..?

10-08-2004, 10:15 PM	#34
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Look, here's what started the whole thing. This little truck was for sale by my house. I got to looking at it, and it was a C-20 truck with normal 3/4 ton type front wheels, but a dually rear. So, I looked under it, and sure enough, it was a converted 3/4 ton. It had coil springs in the rear. All duallys were leaf spring from the factory, so obviously this was a conversion job. Awhile back, I got a good deal on a 3/4 ton longbed 72 truck. I want to put a bed on it like this little red truck has, convert the rear to dual, AND convert the front to a proper dually, so the wheels match all around. It looks to me, like with the right wheels and studs, the rear is possible. I mean, the pictures can't lie right? In the front, it would seem that the rotors from a dually will swap onto my 72 3/4 ton disc spindles. I need a set of wheels and a set of front rotors now. Attached Images __________________ I'm on the Instagram- @Gearhead_Kevin

10-08-2004, 10:20 PM	#35
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	Try to get an old booster truck They have some pretty nifty flatbeds/pto setups on them

10-08-2004, 10:23 PM	#37
67sss Registered User Join Date: Nov 2002 Location: Mt. Vernon, WA.. Posts: 2,322	gotch ya. above post was done B4 I saw your pics.

10-08-2004, 10:38 PM	#39
mcmlxix Collector of Projects Join Date: Apr 2003 Location: Las Vegas Posts: 3,106	This is what I picked up on tuesday. It started out as a RV Camper, but water damage over the years had the camper roof sagging. I forgot to take a before pic. This is the after, 3 days later. You can still see the majority of the rubble in the back ground ... Glove box reads 157" wheel base ... an "RO5" for "DR WHEEL CONVERSION" ... Attached Images __________________ Rich 1972 K5 Blazer CST Click HERE D60 BIG BRAKE UPGRADE Click HERE

10-08-2004, 10:39 PM	#40
mcmlxix Collector of Projects Join Date: Apr 2003 Location: Las Vegas Posts: 3,106	Hey TX... I just bought a C30 Dually camper. I am taking the drive train and cab. I will end up with a 1 ton rolling chassis for sale.I think the glove box read 157" wheel base .... but I dont remember and its dark out! Its also optioned for dual rear wheels but I dont know the ratio... If you or anyone is interested, PM me. It's in Las Vegas (north of the city) Looking for $800. I will also have some "Custom/30 DELUXE" badges, Dark Green Deluxe door pannels in really nice shape with great chrome trim and other misc small parts... but I dont want to turn this into a "parts for sale" thread ...so I'll stop here ... __________________ Rich 1972 K5 Blazer CST Click HERE D60 BIG BRAKE UPGRADE Click HERE

10-08-2004, 10:55 PM	#42
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	OK, thanks man. PM sent. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

10-08-2004, 11:11 PM	#43
BLAZERMAN Currently Blazerless Join Date: Apr 2000 Location: St. Joseph Mo. Posts: 4,826	You guys might want to check out this truck on Ebay, lots of good pics on a dually conversion. http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW Attached Images

10-08-2004, 11:16 PM	#44
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	Cab And Chassis Rearend



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10-08-2004, 11:45 PM	#45
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	All 67-72 duallys were cab and chassis trucks.

10-09-2004, 05:11 AM	#46
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Another option if it came down to it, you don't say what type of 4.10 rear you have, but if it's an eaton and the duallys of the era were eatons then the centers should swap. The catch 2wd rear spring(1/2, 3/4) spacing is wider than the (1 ton) spring spacing which I believe is the same as the 4wd rear spring spacing. __________________ 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

10-09-2004, 07:28 AM	#47
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	Yea I Would Like To Make My C-20 Into Duals In The Rear..... can I....can I....can I.... Last edited by rage'nrat638; 07-12-2007 at 07:05 AM.

10-09-2004, 08:15 PM	#49
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Here's the 72 I'm getting: and the rear axle __________________ 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

10-09-2004, 09:05 PM	#50
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	Dude that truck looks cool with the step bed on it! __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

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