1/2 and 3/4 ton front - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**JIMs70GMC** · 01-22-2004, 12:29 PM

In fourwheelers project superburb, they mentioned running 1/2 ton calipers on their 3/4 ton front dana44 so they could use 15" wheels. Something about the 1/2 ton calipers are slightly smaller and no grinding is necessary. Anybody tried this? Any thoughts or opinions?

CHEVYJEFF · 01-22-2004, 01:18 PM

you will still have to grind some because the caliper mount is bigger due to the bigger diameter of the 3/4 ton rotor. But the calipers are supposed to be the same

**JIMs70GMC** · 01-22-2004, 01:28 PM

I had heard that the 3/4 ton calipers had a larger piston. I ask because I also understand that the 3/4 dana caliper are not as beefy as the dana 60s which respond very well to grinding(as seen on CK5).

Beast388 · 01-22-2004, 10:09 PM

Jim.....I have my original 1/2 ton calipers on my 3/4 axle. I still had to grind to fit 15" rims. It isn't the calipers that cause the need to grind, it is the larger diameter of the 3/4 rotors.

I also compared the original 3/4 ton caliper pistons to the my 1/2 tons, and they were the same.

**JIMs70GMC** · 01-23-2004, 10:33 AM

Ben, you remember the superburb article, were they just smoking crack? I started this because I have a set of 15x10 8-lug rims and I'm buying a 71 GMC 3/4 4x4 and would like to use them. You know keep it simple between the two trucks.

drink2mny · 01-23-2004, 07:33 PM

Yeah the 1/2 and 3/4 d44's calipers are the same size. The D60's are different.
As for using a 1/2 backing plate, I just can't see doing that.The 3/4 ton rotor is bigger than the 1/2. If you could do that I would think everybody would easily convert to 3/4 ton..

As for fitting the 15" rims on 3/4 ton GRIND baby GRIND. I believe with the right offset you don't have to with steel rims, but if they are aluminum you will end up grinding..

I run 15x8 on a d60 front and 14bolt with disc brakes on the back.
had to grind alot on the front and very little on the back..

**JIMs70GMC** · 01-24-2004, 08:40 PM

Thanks you all. I had the parts house pull the rotors so I could visualize, the 3/4 ton rotor is way bigger than the box the 1/2 ton rotor comes in. Grinding might be the option. I have two sets of 15x10 8 lug rims: the US wheel white wagon wheels on my K25 and American Racing white wagon wheels that were on my K25 when I had the BFGs. We'll see which works the best.

Beast388 · 01-24-2004, 11:42 PM

Jim.....here is a pic of my grinding. Not only did I grind on the calipers, but I hammered the backing plate down as well. It was easiest to test fit with just the rim...not tire mounted. It took me about 2 hours per side. My rims have a backspacing of 4.25".

01-22-2004, 12:29 PM	#1
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	1/2 and 3/4 ton front In fourwheelers project superburb, they mentioned running 1/2 ton calipers on their 3/4 ton front dana44 so they could use 15" wheels. Something about the 1/2 ton calipers are slightly smaller and no grinding is necessary. Anybody tried this? Any thoughts or opinions? __________________ 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

01-22-2004, 01:18 PM	#2
CHEVYJEFF Registered User Join Date: Oct 2002 Location: WYLIE TEXAS Posts: 232	you will still have to grind some because the caliper mount is bigger due to the bigger diameter of the 3/4 ton rotor. But the calipers are supposed to be the same __________________ http://members.cardomain.com/chevyjeff 57 2 DOOR HDTP 82 CORVETTE 90 V10 BLAZER 97 REGAL LSR 2100 (BOAT)

01-22-2004, 01:28 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I had heard that the 3/4 ton calipers had a larger piston. I ask because I also understand that the 3/4 dana caliper are not as beefy as the dana 60s which respond very well to grinding(as seen on CK5). __________________ 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

01-22-2004, 10:09 PM	#4
Beast388 Suburbans RULE! Join Date: Jan 2000 Location: Clinton, IA 52732 Posts: 689	Jim.....I have my original 1/2 ton calipers on my 3/4 axle. I still had to grind to fit 15" rims. It isn't the calipers that cause the need to grind, it is the larger diameter of the 3/4 rotors. I also compared the original 3/4 ton caliper pistons to the my 1/2 tons, and they were the same. __________________ --Ben 71 GMC Suburban 4X4 The "Beast" 388 CID Stroker, TH350, NP205, 8-lug D44, 14BFF w/ Detroit, 4.10:1 gears, 4-Wheel Disks 4" Lift, 35" MT/R's.

01-23-2004, 10:33 AM	#5
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Ben, you remember the superburb article, were they just smoking crack? I started this because I have a set of 15x10 8-lug rims and I'm buying a 71 GMC 3/4 4x4 and would like to use them. You know keep it simple between the two trucks. __________________ 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

01-23-2004, 07:33 PM	#6
drink2mny Registered User Join Date: Jun 2003 Location: spokane wa Posts: 2,189	Yeah the 1/2 and 3/4 d44's calipers are the same size. The D60's are different. As for using a 1/2 backing plate, I just can't see doing that.The 3/4 ton rotor is bigger than the 1/2. If you could do that I would think everybody would easily convert to 3/4 ton.. As for fitting the 15" rims on 3/4 ton GRIND baby GRIND. I believe with the right offset you don't have to with steel rims, but if they are aluminum you will end up grinding.. I run 15x8 on a d60 front and 14bolt with disc brakes on the back. had to grind alot on the front and very little on the back.. __________________ Support The Board

01-24-2004, 08:40 PM	#7
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Thanks you all. I had the parts house pull the rotors so I could visualize, the 3/4 ton rotor is way bigger than the box the 1/2 ton rotor comes in. Grinding might be the option. I have two sets of 15x10 8 lug rims: the US wheel white wagon wheels on my K25 and American Racing white wagon wheels that were on my K25 when I had the BFGs. We'll see which works the best. __________________ 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

01-24-2004, 11:42 PM	#8
Beast388 Suburbans RULE! Join Date: Jan 2000 Location: Clinton, IA 52732 Posts: 689	Jim.....here is a pic of my grinding. Not only did I grind on the calipers, but I hammered the backing plate down as well. It was easiest to test fit with just the rim...not tire mounted. It took me about 2 hours per side. My rims have a backspacing of 4.25". Attached Images __________________ --Ben 71 GMC Suburban 4X4 The "Beast" 388 CID Stroker, TH350, NP205, 8-lug D44, 14BFF w/ Detroit, 4.10:1 gears, 4-Wheel Disks 4" Lift, 35" MT/R's.



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