The 1947 - Present Chevrolet & GMC Truck Message Board Network - Finally got those control arm bushings in

ok I'm going answer this the best I can. Lolife is my mentor, not really but I bug him all the time. , Yes you can use your crossmember, and yes you can use the brake booster and master cylinder. Quoting Brad from this site. He says just use the brackets that are mounted on the booster. You'll need to cut part of the bracket away to make it fit flush up against the firewall, also you'll need to extend the rod that goes from the pedal to the booster but other than those things this is a bolt on deal. Look up lolife and Brad they can be more descriptive. I'm new at this too.
Ok this one is by Keith aka lolife
"Drum to Disc" conversions 67-70

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DRUM TO DISC CONVERSIONS 67-70

67-70 truck with

67-70 Crossmember Installed:
1) There are many advantage to leaving your 67-70 crossmember in place to add disc brakes.

2) 67-70 truck owners can now purchase "year specific" standard and drop spindles, from many aftermarket suspension vendors.
* No need to change ball joints.
* No need to change tie rod ends.
* These new "conversion disc brake spindles" are a true "bolt-on" mod to add disc brakes to your truck.

3) The 67-70 a-arms can also be used with any other (71-72 or 73-87) spindle, with a simple ball joint change.
* The upper and lower ball joints and outer tie rods must match the correct year of spindle you choose.

4) You will need a "conversion" rubber brake hose to connect your disc brake caliper to your existing steel brake line.
* 71-72 rubber brake hoses can be adapted.
* Much longer 73-87 brake hoses can also be adapted.
* Aftermarket steel braided brake hoses are an option.

5) Keeping your original 67-70 crossmember allows to to leave the engine and transmission in place.
* No need to remove drivetrain.
* No need to temporarily support the engine, while removing the crossmember.
* Complete disassembly of the front suspension also allows you the ability to clean, inspect, replace or rebuild all the individual components.

Links:
*http://www.classicperform.com/discdrop.htm
*http://www.earlyclassic.com/Tech.asp...20That%20Truck
*http://www.customclassictrucks.com/t...all/index.html

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67-70 truck with

71-72 Crossmember Installed:
1) Your truck's donor 71-72 crossmember came from the factory with disc brakes.

2) "Year Specific" 71-72 drop spindles are readily available.

3) All 71-72 oem and drop spindles only work with HD rotors.
* All 71-72 rotors are the HD version (1-1/4" wide).
* The HD rotors will require matching HD calipers and wheel bearings.

4) 71-72 steering linkage contains 11/16" diameter tie rods.
* Inner Tie rods are LH thread.
* Outer Tie rods are RH thread.
* Inner Tie Rods are a "2-year only" tie rods. (71-72 only)
* Outer Tie Rods are a "2-year only" tie rods. (71-72 only)

5) Steering Linkage:
* All 71-72 oem linkage will work with 71-72 "year specific" oem and drop spindles.

6) A-arms have steel bushings.

7) 71-72 crossmembers have the steel brake line connect the rubber brake hose on the front side of the crossmember.
* Steel reproduction brake line sets are specific to the 71-72 design.

8) Rubber brake hoses are a "2-year only" item. (71-72)

9) 6-lug aftermarket rotors are now readily available if you decide you want to keep your 6-lug style wheels on your 60-62 truck.
* Be aware that the oem 15x6.5 steel 6-lug wheels will not clear your new disc brake conversion.
* You will need to use a set of steel wheels found on the later 73-87 4x4 trucks.

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67-70 truck with

73-87 Crossmember Installed:
1) Your trucks 73-87 donor crossmember came from the factory with disc brakes.
* Using the 73-87 crossmember allows for upgrading to 73-87 style rubber bushed a-arms.
* Most replacement parts are more affordable than the "2-year" specific 71-72 model trucks.
* Most auto parts stores keep these parts "in stock".

2) Drop spindles are readily available,... but there are two versions that must match the two rotor versions below:

3) Rotors:
* There are two different widths of rotors available on the 73-87 model trucks.
3.1) HD or Heavy Duty rotors: (1-1/4" wide version) available from 73-87
* These will require matching HD bearings and calipers.
3.2) LD or Light Duty rotors: (1" wide version) available from 81-87.
* These will require matching LD bearings and calipers.

4) Steering linkage contains 11/16" diameter tie rods.
* Inner Tie rods are LH thread.
* Outer Tie rods are RH thread.
* Inner Tie Rods are 73-87 specific
* Outer Tie Rods are 73-87 specific

5) All 73-87 oem steering linkage will work with your 73-87 spindles.

6) The 1/2 ton a-arms have rubber bushed cross shafts
* (compared to the steel bushings of the 71-72 a-arms)

7) 73-87 crossmembers have the steel brake lines, connect the rubber brake hose, through a hole originally drilled in the 73-87 frame rail.
* Using these crossmembers in the older trucks will require you to fabricate some or all of your steel brake lines.
* (67-70 brake lines connect on the rear side of the crossmember)
* (71-72 brake lines connect on the front side of the crossmember)
* Steel reproduction brake line sets are specific to the 73-87 design with their proportioning valve mounted on a crossmember in front of the engine opposed to hanging below the master cylinder.

8) 73-87 rubber brake hoses are much longer than either the 63-70 drum brake hose or the 71-72 disc brake hose.

9) 6-lug aftermarket rotors are now readily available if you decide you want to keep your 6-lug style wheels.
* To use the 6-lug rotors you must have the 73-87 HD spindles,... since all aftermarket 6-lug rotors are only available in the 1-1/4" wide version.
* Be aware that the oem 15x6.5 steel 6-lug wheels will not clear your new disc brake conversion.
* You will need to use a set of steel wheels found on the later 73-87 4x4 trucks.

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67-70 truck with

71-72 Crossmember Not Yet Installed:
1) Your truck's donor 71-72 crossmember came from the factory with disc brakes.
* You can swap out the entire 67-70 crossmember in one unit.
* Only a few holes will need to be drilled or elongated.
* The best option is to use all of the 71-72 steering components.
(centerlink, tie rods, idler arm, steering box and pitman arm)

2) 67-70 steering linkage use a different centerlink and tie rods, than the 71-72 crossmember you will be installing.

3) 67-70 tie rods are 5/8" diameter,... 71-72 tie rods are 11/16" diameter (with the opposite thread direction).
* 67-70 inner tie rods are RH thread vs. 71-72 inner tie rods (that are LH thread).
* 67-70 outer tie rods are LH thread vs 71-72 outer tie rods (that are RH thread).
* Again,... It's easiest to just use all of the 71-72 steering linkage.
* You can also use all of the 73-87 steering linkage, but you will have to change the outer tie rods to the 71-72 version to match the 71-72 spindle.

4) If you must use your 67-70 centerlink and inner tie rods:
* You will be require to use a "conversion" tie rod sleeve to connect the 67-70 5/8" diameter tie rod,... to the 71-72 11/16" diameter outer tie rod.
* Here is the problem: The 67-70 inner tie rod is RH thread. The 71-72 outer tie rod is also RH thread.
* To correct this,... you must use a 63-70 outer tie rod in the inner location.
* (The 67-70 outer tie rod is LH thread)

5) If you just want to add 71-72 spindles to your existing 67-70 a-arms,... you will need to change the 67-70 upper and lower ball joint to 71-72 upper and lower ball joints.
* The outer tie rod will have to be a 71-72 outer tie rod also. (see Step #4 above)

6) Rubber brake hoses:
* You must change to a disc brake style hose.
* Early Classic Enterprises, and other suspension vendors, make a "conversion" brake hose that will connect the disc brake caliper, to the original 67-70 brake hose steel line location.
* 71-72 hoses is another option. (but I haven't personally confirmed if the steel line connection is the correct size).
* Another option is to use 73-87 hoses, (cheaper to purchase), but they are much longer, and also may need fitting adapters.
* Aftermarket steel braided hoses and AN fittings is another option.

7) You can also just swap all the components from the a-arms out and leave your original 67-70 crossmember in place.
* This will require you to completly disassemble both the original 67-70 suspension and the 71-72 donor suspension.
* This is also a good time to clean, inspect, replace or rebuild any needed components.

Links:
*http://67-72chevytrucks.com/vboard/s...+brake+install.
* Hotchkis Suspension:
http://www.truckinweb.com/tech/suspe...dup/index.html

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67-70 truck with

73-87 Crossmember Not Yet Installed:
1) Your donor 73-87 crossmember came from the factory with disc brakes.
* This swap is almost a direct bolt in, with just a few holes to drill/elongate.

2) The preferred method is to use all of the 73-87 steering linkage:
* This includes the centerlink, inner and outer tie rods, idler arm and steering box. (A great way to gain P/S)

3) If you must use the 67-70 steering components, you will need to change the tie rods:
* The 67-70 inner and outer tie rods are a smaller diameter (5/8") vs. the 73-87 tie rods larger diameter (11/16").
* The 67-70 tie rods are also the opposite thread direction of the 73-87 tie rods.
* 67-70 inner is RH thread vs. 73-87 inner which is LH thread.
* 67-70 outer is LH thread vs. 73-87 outer which is RH thread.

3.1) So to connect the 73-87 spindle to the 67-70 steering centerlink you must use a:
* 67-70 outer tie rod (LH thread) in the inner location.
* connect that to a tie rod "conversion sleeve". (these are sold by many aftermarket suspension companies).
* use a 73-87 outer (RH thread) to connect to your 73-87 spindle.
* Again,... it's much simpler to use all of the 73-87 steering components.

4) Connecting the 73-87 rubber brake lines to the 67-70 steel lines, may require steel line fabrication, or brass "inverted flare" adapters.

5) You can also just swap all the components, from the a-arms out,... and leave your original 67-70 crossmember in place.
* This will require you to completly disassemble both the original 67-70 suspension and the 73-87 donor suspension.
* This is also a good time to clean, inspect, replace or rebuild any needed components.

Links:
*http://67-72chevytrucks.com/vboard/s...+brake+install
*http://www.67-72chevytrucks.com/vboa...d.php?t=357610

*http://www.classictrucks.com/tech/05...ing/index.html

CPP Modular Spindle Install
*http://www.classicperform.com/tech_a....05.09-web.pdf

*16" WILWOOD Install:http://www.customclassictrucks.com/t...10s/index.html

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67-70 Truck With 6-lug Disc Brakes:

6-Lug Drum to 6-Lug Disc Conversions:
1) This 6-lug disc brake swap will include all of the above 5-lug information.

2) The only difference is the use of an aftermarket 6-lug rotor.
* These rotors are new castings.
* These rotors have been drilled with the correct 6x5.5" 6-lug pattern.
* These rotors have the correct 7/16" lug studs that match the original drum brake lug studs.

3) Several aftermarket suspension vendors sell these rotors,... such as:
* ECE (Early Classic Enterprises).
* POL (Performance OnLine).
* CPP (Classic Performance Products).

4) All 63-70 "conversion" stock height and drop spindles will work with these 6-lug rotors.

5) All 71-72 stock oem and drop spindles will work with these 6-lug rotors.

6) If using a 73-87 spindle,... it must be the HD spindle, that works with the 1-1/4" wide rotors.
* The 81-87 LD spindles will not work with these 6-lug rotors.

Links:
*http://www.earlyclassic.com/tech.asp...arly%20Braking
*http://www.earlyclassic.com/tech.asp...h%20And%20Whoa
* http://www.classictrucks.com/tech/05...all/index.html

6-lug Rotors:
*http://67-72chevytrucks.com/vboard/s...ght=Disc+Brake

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60-72 truck with

"Unknown" Crossmember Swap?
* This is where it's hard to determine the correct parts needed.

Here's the break down by year:

Disc Brake Spindle:
*60-70 (Aftermarket Conversion Spindles)
*71-72 (oem or drop)
*73-87 (oem or drop)

C10
Grouped by Differences:
*60-62
*63-70
*71-72
*73-87 (HD 1.25" wide rotors)
*81-87 (LD 1.00" wide rotors)
**Some 81-87 trucks also had the HD rotors**
** All Aftermarket 6-lug "Conversion Rotors Are the HD 1.25" wide version**
C20
*71-87

Rotors:
*71-72 (1.25" wide)
*73-87 (HD 1.25" wide rotors)
*81-87 (LD 1.00" wide rotors)
**Some 81-87 trucks also had the HD rotors**
** All Aftermarket 6-lug "Conversion Rotors Are the HD 1.25" wide version**

Calipers:
*71-72 (1.25" wide)
*73-87 (HD 1.25" wide rotors)
*81-87 (LD 1.00" wide rotors)
**Some 81-87 trucks also had the HD rotors**
** All Aftermarket 6-lug "Conversion Rotors Are the HD 1.25" wide version**

Upper Ball Joint:
Grouped by Differences:
C10
*60-62
*63-70
*71-72
*73-87
C20
*71-87

Lower Ball Joint:
Grouped by Differences:
C10
*60-62
*63-70
*71-87
C20
*71-87

Control Arm Upper Cross Shafts:
Grouped by Differences:
C10
*60-62
*63-72
*73-87
C20
*63-87

Control Arm Lower Cross Shafts:
Grouped by Differences:
C10
*60-62
*63-72
*73-87
C20
*67-86

Inner Tie Rods:
Grouped by Differences:
C10
*60-62
*63-64
*65-70
*71-72
*73-87
C20
*60-64 (drivers side)
*60-64 (pass. side)
*65-70
*71-87

Outer Tie Rods:
Grouped by Differences:
C10
*60-64
*65-70
*71-72
*73-87
C20
*60-64
*65-70
*71-87

Tie Rod Adjusting Sleeves
Grouped by Differences:
C10 and C20
*60-64
*65-70 (5/8" thread)
*71-87 (11/16" thread)

Centerlink:
Grouped by Differences:
*60-62
*63-64
*65-70
*71-72
*73-87

Pitman Arm:
Grouped by differences:
C10
*60-66 Manual
*60-66 P/S
*67-72 Manual
*67-87 P/S (Specify Year When Ordering)
C20
manual:
*60-66
*67-68
*69-70
*71-87
Power Steering:
*69-70
*71-87

Idler Arm
Grouped by differences:
C10
*60-62
*63-66
*67-87 (Specify Year When Ordering)
C20
*60-66
*67-87 (Specify year when ordering)

Steering Box:
Manual
*60-62
*63-66
*67-87
Power Steering
__________________
Keith.

-'71 2wd Blazer- Bagged on TTII's
-'70 Stepside- 1-owner/original paint 250/3-spd
-'69 Short Fleetside Factory 292/Powerglide Project: NO-LIFE

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Last edited by lolife99; 02-07-2011 at 02:14 PM.