axle swap

[Yukon Jack]

I put 3/4 ton axles from a 78 into my 70 K5. I used the 78's master and proportioning valve. I went ahead and just ran new lines for the front brakes and then used rubber brake lines for a 78. Otherwise I would have had to use a number of adapters to make everything work. The front brake hard line is pretty easy to remove and bend up a new piece. For my rear axle I also ran new hard lines on the axle as the existing looked pretty crusty. Then i used a new rubber line for a 78 to connect the axle's hard line to the K5's rear hard lines.

You might find it easier to do run some new lines like I did rather than try to figure out what adapter fittings are needed to make it all mesh. Definitely get the 72's proportioning valve and if possible get it's master cylinder too.