71-72 truck with:
71-72 Crossmember Installed:
1) Your truck's crossmember came from the factory with disc brakes.
2) "Year Specific" 71-72 drop spindles are readily available.
3) All rotors are the HD version (1-1/4" wide).
* This will require matching HD 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 a "2-year only" tie rod. (71-72 only)
* Outer Tie Rods are a "2-year only" tie rod. (71-72 only)
5) Steering Linkage:
* All 71-72 oem linkage will work with 71-72 "year specific" drop spindles.
6) A-arms have steel bushings.
* (compared to the rubber bushings of the 73-87 a-arms)
7) 71-72 crossmembers have the steel brake line connect the rubber brake line on the front side of the crossmember.
* 63-70 brake lines connect on the rear 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)
Links:
*Hotchkis Suspension:
http://www.truckinweb.com/tech/suspe...dup/index.html
71-72 Truck with:
73-87 Crossmember Installed:
1) Your 71-72 trucks already have 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.
* Plus 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) Ball joints:
* 73-87 Uppers are a different.
* 73-87 lowers are the same.
5) 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 (and different from the 71-72 tie rods).
* Outer Tie Rods are 73-87 specific (and different from the 71-72 tie rods).
6) All 73-87 oem steering linkage will work with your 73-87 spindles.
7) Steering Linkage:
* If you swap out your crossmember, it's easiest to just use the 73-87 Steering linkage.
* You can use all of your 71-72 steering linkage, but you will have to change the
outer tie rods to the 73-87 version.
8) The 1/2 ton a-arms have rubber bushed cross shafts
* (compared to the steel bushings of the 71-72 a-arms)
9)73-87 crossmembers have the steel brake line connect the rubber brake line 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.
* (63-70 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.
10) 73-87 rubber brake hoses are much longer than either the 63-70 drum brake hose or the 71-72 disc brake hose.
71-72 Truck with:
73-87 Crossmember Not Yet Installed:
1) This swap is almost a direct bolt in, with just a few holes to drill/elongate.
2) The preferred method is to swap
all of the 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 71-72 steering components, you will need to change the 71-72 outer tie rod to the larger 73-87 version.
4) Connecting the 73-87 rubber brake lines to the 71-72 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 71-72 crossmember in place.
Links:
http://www.classictrucks.com/tech/05...ing/index.html
CPP Modular Spindle Installhttp://www.classicperform.com/tech_a....05.09-web.pdf
16" WILWOOD Install:http://www.customclassictrucks.com/t...10s/index.html