70 GMC 1/2 ton 4x4 Front Disc Conversion Problem...Advice Please

[MyMach5]

My brother, my dad and I are working on the Front disc conversion for my 1970 1/2 Ton 4x4.

Rather than just swap in a whole Disc Dana44 we took mine apart and swapped in the shafts, caliper brackets, spindles, hubs (with all new bearings), etc. I should note here that we did not swap the knuckles.

We got everything together but now the caliper is bumping into the knuckle instead of the "steering bump stop bolt" when you turn the steering wheel all the way left or all the way right.

So we took everything apart again last night and discovered that the six stud-bolts that come out of the knuckle and hold the caliper bracket are clocked a little differently on my 1970 Drum Dana44 than the 1975 Disc Dana44 donor. It appears this difference causes the calipers to be out of place just enough that they hit the knuckle.

So (sorry about the long one here), have any of you guys run into this and is there a fix other than swapping everything back into the donor axle and rolling that under the truck.

Just to answer a question I know you're going to ask; the reason I wanted to keep my axle is that my whole truck was well taken care of and doesn't seem to have ever been abused. I'm the third owner, everything has always been stock, the steering is tight, etc. Basically, it's a known "good". I don't know the history of the donor axle.

Any help you guys can give me would be much appreciated.

[roluje]

just take it back down to the knuckles and use the knuckles from the 75 44 and you'll be fine. Basically you want to use everything from the knuckles out including the knuckles and axles from the 75.

I just did this recently on my 70 k10. Also don't forget about swapping the master cylinder and proportioning valve from something with disk/drum brakes for proper braking. I used a m/c and prop valve from a 72 chevy.

[MyMach5]

Originally Posted by roluje

just take it back down to the knuckles and use the knuckles from the 75 44 and you'll be fine. Basically you want to use everything from the knuckles out including the knuckles and axles from the 75.

I just did this recently on my 70 k10. Also don't forget about swapping the master cylinder and proportioning valve from something with disk/drum brakes for proper braking. I used a m/c and prop valve from a 72 chevy.

Awesome. Thanks. That's what I'll do.

I actually bought the new brake booster/master cylinder/proportioning valve package from one of the online dealers. I know I don't necessarily need new parts but boy are they shiny

I'll post pics of the whole project in the next day or so.

Thanks again for the help.