8 Lug disc conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lrader99 · 10-09-2010, 12:54 AM

What exactly are the parts required to convert a 72 C30 to power front disc brakes. I have not gone and looked at the truck yet but it appears as though it has split wheels, and im sure it still has drum brakes, altough i can see a dual pot master cylinder and it has a brake booster.

If it does indeed need a conversion, what exact parts are required and what are the relative costs associated. These little things will determine wether or not to buy this truck.

I already know it will need wheels and tires, a bed, probably a tune up or so.
Its real easy to drop a couple grand in a hurry

Youngbuck7072 · 10-09-2010, 01:20 AM

If it doesnt already have discs, just buy a pair of discs off a 3/4 axle. (you can usually get these sort of parts from another board member). my K20 has front discs. having discs or drums on the back(IMHO) doesnt really add noticible stopping power, but its nice to have them on the front

Youngbuck7072 · 10-09-2010, 01:22 AM

and do you have any pics of the dually/

ERASER5 · 10-09-2010, 04:06 AM

If you indeed have power drum brakes, you will need spindles, rotors, calipers, brake hose L&R, banjo bolts, the master cylinder, and the proportioning valve. Likely you will need to redo the plumbing a bit too. Except for the plumbing, it really just a bolt on affair.

C10s all when to disc in 1971. C30s might be different.

lrader99 · 10-09-2010, 06:51 AM

Like I said I havent gone to look at it yet, and the pics are quite small, but after having a couple of C10's you kind of get a feel for the problem areas. It could be a total piece of crap though.

It sure would be nice if it does have front discs. I just cant see myself driving this thing every day in atlanta traffic without discs

Youngbuck7072 · 10-09-2010, 11:55 AM

that dually looks TIGHT. and what kind of block is that// 383?

Shaky · 10-09-2010, 12:26 PM

This one says it only fits 3/4 tons. I'm not sure why that is.

http://www.brotherstrucks.com/prodin...ber=DBC8L20-SS

hicktownhotrodder · 10-09-2010, 01:59 PM

for dually trucks the front disc and hub are one piece. they are offset about three inches to allow clearance for the caliper/rim. if memory serves correctly they are the same part number as 73-87 dually two wheel drives-not 100% sure on that.

CE20934 · 10-09-2010, 05:40 PM

It's a '72? It already has disc brakes. Discs were standard in '71 across the light-duty line (10, 20, 30).

lrader99 · 10-09-2010, 06:33 PM

ok awesome. I have 2 72 C10 Cheyennes and they both have discs. I had heard a lot of people talking about drums on these so I just made an assumption. Are the brakes for this C30 the same as are what are on my C10's?

the motor is a 350/TH400 the guy says it is more than the truck needs. Either he doesnt know what real power is or that thing has a real steep gear...I just cant imagine a 350 that's as incredible as he is describing it.

you guys think its a good buy @ $2500?

I agree, from the pictures it looks like a sharp truck. Im worried about the wheels and tires though. putting 6 tires on it would be close to $1000 and thats hoping that those arent two piece wheels

Youngbuck7072 · 10-09-2010, 07:21 PM

Quote:

Originally Posted by lrader99

ok awesome. I have 2 72 C10 Cheyennes and they both have discs. I had heard a lot of people talking about drums on these so I just made an assumption. Are the brakes for this C30 the same as are what are on my C10's?

the motor is a 350/TH400 the guy says it is more than the truck needs. Either he doesnt know what real power is or that thing has a real steep gear...I just cant imagine a 350 that's as incredible as he is describing it.

you guys think its a good buy @ $2500?

I agree, from the pictures it looks like a sharp truck. Im worried about the wheels and tires though. putting 6 tires on it would be close to $1000 and thats hoping that those arent two piece wheels

IDK about 2500$. non of the wheels on it are probably two piece. i would check for rust and other things that would help you bring the price down. how many miles does the truck have on it? and probably the reason that he thinks that the motor is more than the truck needs is because it has no bed/deck and it looks like that motor has some aftermarket goodies on it.

lrader99 · 10-09-2010, 06:35 PM

i guess the brake question is a dumb one considering my C10's are 5 lug not 8...but your saying that all '72 C class trucks(10,20,30) had front disc?

CE20934 · 10-09-2010, 07:20 PM

All 1/2, 3/4, and 1-ton trucks--2WD & 4WD--had disc brakes from the factory in '72.

(I make no guarantees about a '72 K30 as GM did not make a mass-market 4WD 1-ton until '76 or so, but that's nitpicking.)

lrader99 · 10-09-2010, 07:34 PM

why do you postulate that non of the wheels are the original 2 piece? because they look like radials not bias plys? i am sure it has its issues. he is asking $2500 and has been sitting on it for a while, im sure i could talk it down to 2000 or maybe even 1500. Mileage is unknown. I dont know much about 1 tons, what is a normal price for these things?

Youngbuck7072 · 10-09-2010, 10:41 PM

Quote:

Originally Posted by lrader99

why do you postulate that non of the wheels are the original 2 piece? because they look like radials not bias plys? i am sure it has its issues. he is asking $2500 and has been sitting on it for a while, im sure i could talk it down to 2000 or maybe even 1500. Mileage is unknown. I dont know much about 1 tons, what is a normal price for these things?

i have no idea. i know that finding a stock one is more rare than finding a stock C/K-10/20. as for the two piece rims, i dont think that they would put those as duals, but idk about the front.

ERASER5 · 10-10-2010, 01:40 AM

There are tons of 2 piece duels. Most people try to replace them with one piece, but there are still lots out there.

hicktownhotrodder · 10-12-2010, 09:24 AM

the motor is a 350/TH400 the guy says it is more than the truck needs. Either he doesnt know what real power is or that thing has a real steep gear...I just cant imagine a 350 that's as incredible as he is describing it.

the reason for that is because it has a 4.11:1 or a 4.56:1 rear ratio, as they were the only two options in the eaton rear ends. but these trucks are a lot of fun under 60 mph

10-09-2010, 12:54 AM	#1
lrader99 Registered User Join Date: Apr 2009 Location: kennesaw Ga Posts: 89	8 Lug disc conversion What exactly are the parts required to convert a 72 C30 to power front disc brakes. I have not gone and looked at the truck yet but it appears as though it has split wheels, and im sure it still has drum brakes, altough i can see a dual pot master cylinder and it has a brake booster. If it does indeed need a conversion, what exact parts are required and what are the relative costs associated. These little things will determine wether or not to buy this truck. I already know it will need wheels and tires, a bed, probably a tune up or so. Its real easy to drop a couple grand in a hurry

10-09-2010, 01:20 AM	#2
Youngbuck7072 Registered User Join Date: Sep 2010 Location: Eugene, Or. Posts: 322	Re: 8 Lug disc conversion If it doesnt already have discs, just buy a pair of discs off a 3/4 axle. (you can usually get these sort of parts from another board member). my K20 has front discs. having discs or drums on the back(IMHO) doesnt really add noticible stopping power, but its nice to have them on the front __________________ ........................ __ ............._______\|__\____ ............\|_({})______({})] ................(O)..........(O)

10-09-2010, 01:22 AM	#3
Youngbuck7072 Registered User Join Date: Sep 2010 Location: Eugene, Or. Posts: 322	Re: 8 Lug disc conversion and do you have any pics of the dually/ __________________ ........................ __ ............._______\|__\____ ............\|_({})______({})] ................(O)..........(O)

10-09-2010, 04:06 AM	#4
ERASER5 Registered User Join Date: Jun 2006 Location: Indiana Posts: 4,859	Re: 8 Lug disc conversion If you indeed have power drum brakes, you will need spindles, rotors, calipers, brake hose L&R, banjo bolts, the master cylinder, and the proportioning valve. Likely you will need to redo the plumbing a bit too. Except for the plumbing, it really just a bolt on affair. C10s all when to disc in 1971. C30s might be different. __________________ '70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60

10-09-2010, 06:51 AM	#5
lrader99 Registered User Join Date: Apr 2009 Location: kennesaw Ga Posts: 89	Re: 8 Lug disc conversion Like I said I havent gone to look at it yet, and the pics are quite small, but after having a couple of C10's you kind of get a feel for the problem areas. It could be a total piece of crap though. It sure would be nice if it does have front discs. I just cant see myself driving this thing every day in atlanta traffic without discs

10-09-2010, 11:55 AM	#6
Youngbuck7072 Registered User Join Date: Sep 2010 Location: Eugene, Or. Posts: 322	Re: 8 Lug disc conversion that dually looks TIGHT. and what kind of block is that// 383? __________________ ........................ __ ............._______\|__\____ ............\|_({})______({})] ................(O)..........(O)

10-09-2010, 12:26 PM	#7
Shaky Six in a row makes it go... Join Date: Mar 2009 Location: Vacationland: Maine Posts: 1,346	Re: 8 Lug disc conversion This one says it only fits 3/4 tons. I'm not sure why that is. http://www.brotherstrucks.com/prodin...ber=DBC8L20-SS __________________ 67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce

10-09-2010, 01:59 PM	#8
hicktownhotrodder Rollin Coal Join Date: May 2009 Location: Winnebago Illinios Posts: 131	Re: 8 Lug disc conversion for dually trucks the front disc and hub are one piece. they are offset about three inches to allow clearance for the caliper/rim. if memory serves correctly they are the same part number as 73-87 dually two wheel drives-not 100% sure on that. __________________ I have three letters to all these import guys: God-Made-Chevy 04 GMC Sierra 2500HD Duramax 1972 Chevrolet C-30 Dually Pickup stock? 350 SM465 four speed 1977 GMC K-35, TH-400, 4X4 450 horse 454(dad's) 1993 Dodge cummins 5-speed DEAD!!

10-09-2010, 05:40 PM	#9
CE20934 Senior Member Join Date: Apr 2002 Location: Help! I'm in an office park with its own network of freeways! Posts: 470	Re: 8 Lug disc conversion It's a '72? It already has disc brakes. Discs were standard in '71 across the light-duty line (10, 20, 30). __________________ '67 C20--427 tall deck/SM420, 4.10 HO52 (Michigan has not been kind to the Old Man) '95 Caprice--355 LT1/T56/3.42 8.5" 10-bolt (daily driver, almost 300k on the chassis) '07 Outback--wife's car. 125k & counting. No head gasket or transmission issues yet. fingers crossed

10-09-2010, 06:33 PM	#10
lrader99 Registered User Join Date: Apr 2009 Location: kennesaw Ga Posts: 89	Re: 8 Lug disc conversion ok awesome. I have 2 72 C10 Cheyennes and they both have discs. I had heard a lot of people talking about drums on these so I just made an assumption. Are the brakes for this C30 the same as are what are on my C10's? the motor is a 350/TH400 the guy says it is more than the truck needs. Either he doesnt know what real power is or that thing has a real steep gear...I just cant imagine a 350 that's as incredible as he is describing it. you guys think its a good buy @ $2500? I agree, from the pictures it looks like a sharp truck. Im worried about the wheels and tires though. putting 6 tires on it would be close to $1000 and thats hoping that those arent two piece wheels

10-09-2010, 06:35 PM	#12
lrader99 Registered User Join Date: Apr 2009 Location: kennesaw Ga Posts: 89	Re: 8 Lug disc conversion i guess the brake question is a dumb one considering my C10's are 5 lug not 8...but your saying that all '72 C class trucks(10,20,30) had front disc?

10-09-2010, 07:20 PM	#13
CE20934 Senior Member Join Date: Apr 2002 Location: Help! I'm in an office park with its own network of freeways! Posts: 470	Re: 8 Lug disc conversion All 1/2, 3/4, and 1-ton trucks--2WD & 4WD--had disc brakes from the factory in '72. (I make no guarantees about a '72 K30 as GM did not make a mass-market 4WD 1-ton until '76 or so, but that's nitpicking.) __________________ '67 C20--427 tall deck/SM420, 4.10 HO52 (Michigan has not been kind to the Old Man) '95 Caprice--355 LT1/T56/3.42 8.5" 10-bolt (daily driver, almost 300k on the chassis) '07 Outback--wife's car. 125k & counting. No head gasket or transmission issues yet. fingers crossed

10-09-2010, 07:34 PM	#14
lrader99 Registered User Join Date: Apr 2009 Location: kennesaw Ga Posts: 89	Re: 8 Lug disc conversion why do you postulate that non of the wheels are the original 2 piece? because they look like radials not bias plys? i am sure it has its issues. he is asking $2500 and has been sitting on it for a while, im sure i could talk it down to 2000 or maybe even 1500. Mileage is unknown. I dont know much about 1 tons, what is a normal price for these things? Last edited by lrader99; 10-09-2010 at 07:41 PM.

10-10-2010, 01:40 AM	#16
ERASER5 Registered User Join Date: Jun 2006 Location: Indiana Posts: 4,859	Re: 8 Lug disc conversion There are tons of 2 piece duels. Most people try to replace them with one piece, but there are still lots out there. __________________ '70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60

10-12-2010, 09:24 AM	#17
hicktownhotrodder Rollin Coal Join Date: May 2009 Location: Winnebago Illinios Posts: 131	Re: 8 Lug disc conversion the motor is a 350/TH400 the guy says it is more than the truck needs. Either he doesnt know what real power is or that thing has a real steep gear...I just cant imagine a 350 that's as incredible as he is describing it. the reason for that is because it has a 4.11:1 or a 4.56:1 rear ratio, as they were the only two options in the eaton rear ends. but these trucks are a lot of fun under 60 mph __________________ I have three letters to all these import guys: God-Made-Chevy 04 GMC Sierra 2500HD Duramax 1972 Chevrolet C-30 Dually Pickup stock? 350 SM465 four speed 1977 GMC K-35, TH-400, 4X4 450 horse 454(dad's) 1993 Dodge cummins 5-speed DEAD!! Last edited by hicktownhotrodder; 10-12-2010 at 09:26 AM.



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