School me on swapping 6 to 5 lug, lowering and converting to power brakes all at once

[Rob68c10]

Ok I have a 68 short bed and I want to do a 4/6 drop on it, rebuild the front suspension, and convert to power brakes all in one shot. First let me tell you what I have.

I have:

-'72 5-lug front suspension
-'72 5-lug rear
-power brake booster from the '72
-cab and pedal assembly from '72


My questions:

Is it easiest and cheapest to use the '72 front end to convert to 5 lug/disk brakes/and lower it?

What modifications am I going to need to install the power brake setup?

Should I go ahead and do the rear disks now or is that something I can do later down the road if I want without too much hassle?

What are some things I need to consider before doing this? I have read something where the rear tires do not sit in the fender correctly? Are there any other need to know things like this?

I have looked into the ECE 4/6 drop, any other suggestions?

Suggestions on brand/kit for the front end rebuild?

[Fitz]

Originally Posted by Rob68c10

My questions:

Is it easiest and cheapest to use the '72 front end to convert to 5 lug/disk brakes/and lower it?

What modifications am I going to need to install the power brake setup?

Should I go ahead and do the rear disks now or is that something I can do later down the road if I want without too much hassle?

What are some things I need to consider before doing this? I have read something where the rear tires do not sit in the fender correctly? Are there any other need to know things like this?

I have looked into the ECE 4/6 drop, any other suggestions?

Suggestions on brand/kit for the front end rebuild?

Pittman arm on the 72 suspension is different length than the 67-68 front end and I believe the tie rod ends are different as well. The PO of my 67 stepside used a bastard mix of original and a aftermarket parts that did not work well together so, I used the ECE drop spindles and springs for a 4 in drop in front, calipers and replaced the steering box with their fast ratio unit. New Moog ball joints and a set of KYB shocks to round it out. If you leave drums on the rear you will need a disc/drum proportioning valve which must be replaced with a disc/disc unit when you add the read discs. I did mine all at once so I never had to worry about the prop valve. The booster needs the "long" actuating rod for the master cylinder and you will need the new parts for the pedal linkage and mounting brackets for the booster.

My set-up is probably unique because of the booster...I did not have room for anything larger than a 7 inch diameter booster (stock unit is 10 inches) so I used a dual diaphragm unit with pedal clevis, brackets and master cylinder from carolina Classic trucks. The conversion to power disc is straightforward.

The 72 crossmember is different from the 67-68 so talk to your vendor BEFORE you buy....Stan at Early Classics is very knowledgeable so, if you call, he will help you pick the right stuff. After sorting out the correct anti sway bar mounts, idler arm, pittman arm and tie rod ends with him, I went from before to after in one day.

[Rob68c10]

Originally Posted by Fitz

Pittman arm on the 72 suspension is different length than the 67-68 front end and I believe the tie rod ends are different as well. The PO of my 67 stepside used a bastard mix of original and a aftermarket parts that did not work well together so, I used the ECE drop spindles and springs for a 4 in drop in front, calipers and replaced the steering box with their fast ratio unit. New Moog ball joints and a set of KYB shocks to round it out. If you leave drums on the rear you will need a disc/drum proportioning valve which must be replaced with a disc/disc unit when you add the read discs. I did mine all at once so I never had to worry about the prop valve. The booster needs the "long" actuating rod for the master cylinder and you will need the new parts for the pedal linkage and mounting brackets for the booster.

My set-up is probably unique because of the booster...I did not have room for anything larger than a 7 inch diameter booster (stock unit is 10 inches) so I used a dual diaphragm unit with pedal clevis, brackets and master cylinder from carolina Classic trucks. The conversion to power disc is straightforward.

The 72 crossmember is different from the 67-68 so talk to your vendor BEFORE you buy....Stan at Early Classics is very knowledgeable so, if you call, he will help you pick the right stuff. After sorting out the correct anti sway bar mounts, idler arm, pittman arm and tie rod ends with him, I went from before to after in one day.

Thanks for the info. Sounds like I just need to do it right the first time and do the disk brake conversion for the rear. And also sounds like I need to just call ECE.

I have the booster/master cylinder/pedal assembly from the 72 so I should be ok there.

Sounds like I need to save a little more cash too.

[lolife99]

Did you see this thread?
http://67-72chevytrucks.com/vboard/s...68&postcount=4

Specifically this section:
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.

[lolife99]

Read all of that thread.
There is good info there.
(not just the part I posted)

ECE would be my first choice for 67-72 parts.
Do you plan to lower it any?
Edit:
I just re-read your original post.
I see the 4/6 drop now.

[Rob68c10]

Originally Posted by lolife99

Read all of that thread.
There is good info there.
(not just the part I posted)

ECE would be my first choice for 67-72 parts.
Do you plan to lower it any?

Sorry I did not see that thread. Very good info like you said. Thanks!

[lolife99]

I re-read your original post.
I see a few things in it that I originally didn't.
1) 4/6 drop
2) total suspension rebuild.

Like I have posted before, when it comes to "crossmember swaps",...
I say sell your 72 crossmember to fund your parts.
If you have the steering linkage, save that and use all the parts.
But from the a-arms out,... what will you re-use?
(maybe the dust shield behind the rotors)

You are buying new drop spindles, ball joints, tie rods etc.
Do you need the old rotors and caliper?
They are cheap to buy new.

Bearings will be new.
Brake hoses need to be new.
No need to swap the crossmember itself.
Since you can now buy year specific drop spindles,... in your case,... 67-70 spindles,... there is no needs to change the a-arms.

The only advantage to using the 72 parts, is that it would allow you to rebuild everything BEFORE you actually swap parts.
But I wouldn't swap the crossmember itself.