1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

Hello! A friend just picked up a 70 3/4ton 4x4 pickup with front drum brakes. I believe any axle from 71-87 will bolt in place of his current axle. Is that correct? I believe he will also need a new master cylinder to match. Will a 71+ master cylinder bolt up and work fine? And can he do the same with the front brake lines? Thank you!

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

The short answer is yes. To the best of my knowledge the disc axle is 3" wider. Not a big deal for most. Yes you will need to change the master. Also a new proportioning valve.
I'm currently adding discs to my 69 closed knuckle 44. Not the easy route...... Using parts from a 74 K20. Anything new I buy for a 72 K20. So far the brake lines were to short. Had to have some made. Also the master reservoirs were reversed. Smaller front goes to the rear brakes, larger rear goes to the front brakes. I'll have to make lines to correct the hook up to the pp valve.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

I have a '66 closed knuckle I would like to put disks on. What did you have to do to use the newer style disks? Can you go into this swap a little deeper?
Thanks.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

What is he doing with his old axle?
We are re-doing a 1970 K2500 GMC with drum brakes. It appears that the 1970 was the bastard of the bunch. (one year only) I could use some front hubs.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

He'll probably be getting rid of it. I was telling him he might be best off to get the whole front brake line setup off a square body (including the prop valve) to make everything more simple.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

PM me if he will be getting rid of it. Like I said, I could use some front hubs. I'm currently going for a restoration rather than a driver, but I may have to make some concessions somewhere.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

b.sharp I don't know how to post a link to the post. Do a search for "closed knuckle Dana 44 disc brake swap". I'm not done yet. I'll post results when I can.

Re: 1970 3/4 ton 4x4 front drum to disc brake swap questions.
 

b.sharp--ck out my build thread. It has all the info for a k10 but a k20 would be the same process.