Will 73-87 3/4t disc brake spindles fit a 68?

[thecatseye66]

I posted a thread this past weekend to see if anyone knew what the options were for putting my front drum brakes out to pasture but got no answers.
If anyone has pulled off a swap to front disc brakes on a C-20 let me know how you did it so I can piece it together.

[cadiac]

I've been told more than once that the spinles from a 71-72 will swap right into an earlier truck. How far back? Dunno.-? I bought the spindles/rotors and calipers from a 71 for my 69. They have sat in the shed, -meanwhile I've got another 71 frontend and a complete 72 frame. Now stuff to do a couple extra swaps, and a complete drum frontend. I'm switching to 72 booster/master cylinder. Don't know anything else for now.

[thecatseye66]

ttt

[69 longhorn]

Use the ball joints & all the steering linkage from the 73-up truck, & its a bolt in. you may need to grind the steer stops on the spindles to get the turning radius straightened up, if you are using the 68 lower arms(no big issue tho).... L

[67-Cowboy]

I finally got the info you and I both have been looking for, these HIGH DOLLAR after market guys are selling the($800.00) kit for disk brakes and it's OEM parts ! What a bunch of snakes, just go to the recking yard and buy 73-87 stuff and save a ton of money !!!

[Don Brace]

My 69 3/4 has the complete suspension from a 96 3/4 van, all but the cross member and the sway bar as they were too wide. I took the A arms and the spindles off the 96 as a unit and bolted them onto the 69. I used the 69 springs. It took my son and I about six hours to make the swap.

[thecatseye66]

Originally Posted by Don Brace

My 69 3/4 has the complete suspension from a 96 3/4 van, all but the cross member and the sway bar as they were too wide. I took the A arms and the spindles off the 96 as a unit and bolted them onto the 69. I used the 69 springs. It took my son and I about six hours to make the swap.

You aren't kidding?
What steering linkage did you use? 69 or 96? Tie rod end issues?
96 master-cylinder or old disc/drum w/booster on truck?
This is supercool information Don. Thanks tons.
This board ROCKS

[Don Brace]

The tie rods from the 96 were too long to use on the 69. The 69 already had a power brake unit so I used that one. Basically what we did was unbolt the 96 suspension and the 69 suspension at the cross shafts and put the 96 suspension on the 69. Works great.

[hgs_notes]

Just curious, how did the wheel alignment work out? Which specs did they use?

FYI, I have 73 calipers on my stock 71 rotors. The brake line connection to the caliper was slightly different, otherwise it's identical.

HG

[Don Brace]

HG
I think the guy used the 69 spec to do the alignment. He didn't know the new suspension was from a 96. The only difficult part of the installation was rerouting the brakelines. I used the old drum lines and should have made new hard lines for the disk.

[chevy283]

i use a 91 sub on my 65 I had no tie rod end issues i did swap the idler arm so that i didn't have to drill for that the crossmember has 4 hole the dont linup so i'll have to drill. I use the brake booster and brake lins it went right in. the cool part it was free.

[thecatseye66]

Originally Posted by Don Brace

HG
The only difficult part of the installation was rerouting the brakelines. I used the old drum lines and should have made new hard lines for the disk.

So did you just used the flexible brake hoses to the calipers from the 96 with the original hard frame lines from the 69?

I know you said the truck already had a booster so yo used it, but did you change the master cylinder from the one with the equal-size reseviors to the one that has the bigger front resevior like a standard disc/drum setup?

What about the proportioning valve?

[thecatseye66]

Originally Posted by 69 longhorn

Use the ball joints & all the steering linkage from the 73-up truck, & its a bolt in. you may need to grind the steer stops on the spindles to get the turning radius straightened up, if you are using the 68 lower arms(no big issue tho).... L

I just bought the complete front suspension and brake system-- a-arms to brake booster with all steering linkage and brake lines out of an '83 for 125 bucks. I have to go pull it all out in the morning.

You said I might need to grind the steer stops if I use the 68 lower arms: Do you know if I can I just use the lower arm -- do a complete swap of both a-arms and eveerything else from the 83? Anybody?

[Don Brace]

thecatseye66
I used the drum brake master cylinder. It seems to work okay. The flex lines I used were from the 96 I think.

[69 longhorn]

You can swap the lower arms, & the spindles,steering linkage,brakes......or if you have the complete cradle assy, you can swap it in. You will have to egg a couple bolt holes on the frame to fit it (no biggie tho). L

[thecatseye66]

Originally Posted by 69 longhorn

You can swap the lower arms, & the spindles,steering linkage,brakes......or if you have the complete cradle assy, you can swap it in. You will have to egg a couple bolt holes on the frame to fit it (no biggie tho). L

Thanks for all the great info you guys! When I do this swap I'll take a ton of pictures and post a "how-to" thread.

I'd rather not change the crossmember if I can avoid it--this is an original BB truck with only 42,000 miles and drilling out the frame if I can avoid it sounds like a better solution even if it becomes a little more work. I understand about having to use the whole steering linkage and the donor master cylinder so I'll even try and use the hard lines if I can along with the proportioning valve.

What I'm still confused about is the lower a-arm/ball joint issue. Is the lower a-arm from the 68 going to be in the way of the new disc spindle--making it not turn properly--or is it a ball-joint fitment issue? In other words, can I use my original lower a-arm if I use a ball joint from the 83 (I'll install a new set)? Will the newer ball joint fit in the older a-arm? I keep hearing that the steering stops get in the way but I can grind that off, can't I?

[69 longhorn]

Originally Posted by thecatseye66

Thanks for all the great info you guys! When I do this swap I'll take a ton of pictures and post a "how-to" thread.

I'd rather not change the crossmember if I can avoid it--this is an original BB truck with only 42,000 miles and drilling out the frame if I can avoid it sounds like a better solution even if it becomes a little more work. I understand about having to use the whole steering linkage and the donor master cylinder so I'll even try and use the hard lines if I can along with the proportioning valve.

What I'm still confused about is the lower a-arm/ball joint issue. Is the lower a-arm from the 68 going to be in the way of the new disc spindle--making it not turn properly--or is it a ball-joint fitment issue? In other words, can I use my original lower a-arm if I use a ball joint from the 83 (I'll install a new set)? Will the newer ball joint fit in the older a-arm? I keep hearing that the steering stops get in the way but I can grind that off, can't I?

The balljoints are different, but the later disc brake pcs will fit your original A arms. The trouble with the steer stop, is the difference in the placement of the stop on the arm (drum brake spindle vs disc brake spindle). on the 3/4ton , the parts are the same from 71-87(balljoints & tierods). just order the suspension pcs for the yr of the spindle, & you will be ok.....after that, you can opt to grind the stops as needed, or swap the later lower arms on the truck. best of luck.... L