putting 71-72 brakes on a 68?

[54Caddy]

On my dads 68 we just swapped out the whole a-frame. It works fine still have the regular master cylinder off of the 68 with no booster, and the original proportioning valve of the 68 also and it stop perfect man.

[sixtyeightchevykid]

do you think i will be able to use the stock 68 arms ans just put in the later model spindles rotors etc.?

[54Caddy]

You should be able to man. As far as i know you can do the swap just with spindles. Hell look at the conversion kits they just come with the spindle not the a-arms. Go for it man.

[michael bustamante]

the ball joints will not work if you go this route, youll have to change to 73+ ball joints as well, good idea to swao em out anyways. If your modding on a budget, go to the scrap yard and pull the whole crossmember assy off a 73 and up truck. it bolts right in and you anly have to drill like 2 holes in the fram and youll save yourself alot of headache, if you do a search theyll be alot of info on this

[seekhunt]

I put the complete crossmember from a 76 1/2 ton onto my 67 1/2 ton. I used the master and proportioning valve from the 76. You need to increase the bore of the rear wheel brake cylinders to the 1 1/16 variety or your rear tires when braking will lock up too easy in the wet. The inner tie rod end is from an 89 3/4 ton. Have the machine shop knock about 1 1/4 inches of thread off (That'll leave you with about 5 inches to the good).
So that being said, now you have 5 bolt lugnut pattern up front and 6 bolts on the rear. So for the rear I used a 3 series diff housing from the mid 70's or 80's so I dont have to run around with 2 spare tires. Weld new spring purchases in new locations. Pete

[SCOTI]

Originally Posted by seekhunt

I put the complete crossmember from a 76 1/2 ton onto my 67 1/2 ton. I used the master and proportioning valve from the 76. You need to increase the bore of the rear wheel brake cylinders to the 1 1/16 variety or your rear tires when braking will lock up too easy in the wet. The inner tie rod end is from an 89 3/4 ton. Have the machine shop knock about 1 1/4 inches of thread off (That'll leave you with about 5 inches to the good).
So that being said, now you have 5 bolt lugnut pattern up front and 6 bolts on the rear. So for the rear I used a 3 series diff housing from the mid 70's or 80's so I dont have to run around with 2 spare tires. Weld new spring purchases in new locations. Pete

It's not an absolute on the rear brake cylinder size. Larger diameter wheel/tire combo's possibly won't see the same issue. I did the post-73 suspension/brake swap to my 68 (using the original 68 c.member) & did not have issues w/lock-up using 29" tall tires. I used a master cyl & power booster for a 71-72. All the brake lines were post-73 up to the OE union under the pass side of the cab. From that union back it was OE 68 lines/cylinders.

[seekhunt]

Thats a good point. Its totally dependent on your situation, and as with anything, do a lot of reading and research so you dont have to completely reinvent the wheel every time you come up with something you'd like to do. Us older guys have been through many projects, and its important to just take it all in, and then just do what you were going to do anyway!

[gcburdic]

68....asked this question awhile back....see if this thread helps any....http://67-72chevytrucks.com/vboard/s...d.php?t=381785

[sixtyeightchevykid]

ok so i would also have to get new ball joints for a 73+. now all i have to do is find a 73 and up parts to do this

[63chevyll]

humm, i thought the frames were narowwer on the 72-older trucks.

And ive been using the orig crossmembers from 72

[sixtyeightchevykid]

again sorry its been a while, i found a 73 what i and going to get the parts off of tomorrow if it doesnt rain, i got the spindles and rotors the other day and cleaned them up and painted the spindles, going to grab the calipers, master cylinder, booster, proportioning valve, hard lines, tie rods ends, center link, and maybe the rims,.
im going to get new ball joints and wheel bearings, ill try tokeep you guys updated a little beter from now on, also im getting a rearend out of a 71 or 72, so that i can keep the rear coils and go with the matching 5 lug, and something a little better than 4.11 gears lol