Looking for help on K-20 drum to disk convertion
 

Hey guys, I'm in need of some help. I'm not new to the 67-72 truck world, I've owned several. however I am new to the "k" world. I was recently able to acquire my dream truck. A 1970 k-20 4 speed truck. It needs love but I finally got one. My first priority is a obvious one. Brakes. I'm looking for information on converting in over to disk. I know there are numerous threads on the topic and it makes my head spin sorting through them all so I apologize for starting a another one. from everything I have found so far I need a newer 8 lug dana 44. I called my local junk yard and found a 76 k20 truck dana 44 for $200. I'm not sure the ratio of my truck nor the junk yard axle. I would like to possibly switch knuckles if that's possible? any info, advice, or pictures would be so helpful. This page is the best and so is the 67-72 community. Thank you for taking the time to read my mess :metal:

Re: Looking for help on K-20 drum to disk convertion
 

Welcome to the K20 club! They are the best of the 67-72’s in my totally biased opinion! I do believe you can swap the knuckles over, though I have no experience with that particular swap. I think if it was me, I’d look for an axle with the correct ratio, freshen the bearings and such up, and swap the whole thin. Seems a lot easier to me than mixing and matching parts. I’m sure Tim or one of the other guys here may be able to tell you what you looking at for a knuckle swap. I would love to see some pictures of your new baby!

Re: Looking for help on K-20 drum to disk convertion
 

The 1970 has the D44 one year aardvark. First year open knuckle last year drum. Your front most likely has 45-11(4.09) gears in front. I would get the junk yard axle, go through it, clean it up and swap in the 4.09 if needed. You can also drop in a Dana 60, something to think about, but most of the military surplus is eaten up, plus those have 4.56 gears. Anyhow, short answer, I would do an axle swap and seriously consider a 60. :chevy:

j

Re: Looking for help on K-20 drum to disk convertion
 

Dana 44 and 10 bolt from the 'square body' will bolt right up (just did it myself). Unless you are hard core offroader, both will be fine. 10 bolt is considered a bit stronger BTW.

Just wait and find one with the gear ratio you want. If you were considering regearing, that would be the time though. Rear axles from square bodies are not bolt in however, the spring and shock mounts must be moved.

Re: Looking for help on K-20 drum to disk convertion
 

Unless it’s a 1ton single rear wheel. That is a bolt in minus 1 shock mount.

Re: Looking for help on K-20 drum to disk convertion
 

Thank you guys for all the help. I pulled the cover tonight. It is a 45-11 (4.09) I thought about a Dana 60 swap but honesty there’s not much need. This is going to be a curser not so much a off roader or a trailer queen just a good driver so a Dana 44 should be just fine. Once I figure out how to post pictures I’ll put some up. She’s not the prettiest but it’s a start. A good power washing did it wonders.

Re: Looking for help on K-20 drum to disk convertion
 

He’s a few pictures of the old girl. I’ll be sure to add more as progress begins

Re: Looking for help on K-20 drum to disk convertion
 

Heck yea! That is great looking truck. Looks like a solid starting point especially for Michigan. I can’t wait to see what you do with it.

Re: Looking for help on K-20 drum to disk convertion
 

Wish I would have understood that distinction before buying a 3/4 ton rear for mine!

Re: Looking for help on K-20 drum to disk convertion
 

Keep those locking hubs! Nice project truck, the 4x4s are fun. :chevy:


j

Re: Looking for help on K-20 drum to disk convertion
 

Thank you. It looks better in pictures then it does in person. The cab is pretty rough but it is a factory a/c truck. The box is rough too, but it did come with a rust free bed.
The story behind this truck is very cool. I traded my first truck, a 1971 c-30 that I’ve owned since I was 15. The truck that started my love affair of the 67-72’s for this truck. But this is where the story gets good. I bought my 71 from a family friend. This k-20 came from the brother of the family friend I bought the 71 from so it is back in their family and I still get to see and enjoy my first truck on a regular basis. (I apologized it’s a lot to follow along with)

Re: Looking for help on K-20 drum to disk convertion
 

all this talk about axle swaps and I completely over looked everything else. what about the proportioning valve? what should I do there?

Re: Looking for help on K-20 drum to disk convertion
 

Were you just swapping the front or both? When I changed to disc/disc I had a soft pedal and poor braking. I called Pirate Jack's and they set me up with a new MC and Prop valve. Bolted right up and brakes work great.

Looks like it is PN MCK111DLM and was $105.

If you do rears, you'll also want to consider the parking brake.

Re: Looking for help on K-20 drum to disk convertion
 

very nice truck!!

Re: Looking for help on K-20 drum to disk convertion
 

Is any Dana 44 a straight bolt-in for the front axle or for a junkyard find should I look at specific years, etc.?

Re: Looking for help on K-20 drum to disk convertion
 

As long as it from a GM truck from 67-87(91 blazer/jimmy, suburban) it will bolt in. 77ish and later normally are the gm 10 bolt which is nearly identical to the 44.