[57taskforce]

Looks pretty solid. Looks like a K20 frame which is an excellent start.

That is a ‘70 front axle like you thought. Np205 is correct, I believe you’ll need later wheels to work with the disks but I’ve never had drums so I could be wrong. If you can find a ‘71-76ish GM external hub 3/4 ton front axle you can swap your red dials in place of the blue or yellow dials if you’d like to keep them, and gain disks. Later axles use internal hubs. The hub dial housings that are cracked are not reproduced but they are still around used. You shouldn’t have much trouble finding some, you could post a want to buy in the parts board.

Any axle from a 71-87(91 for 3/4 ton suburbans,1 ton crews) 3/4-1 ton solid front axle 4x4 will bolt in and work just fine, this is how I would swap to disks.

Ohh and It looks like it’s got a lift on it. Rear blocks, four leaves in the front packs.
It’s also possible that is a ‘72 frame, based on the strap of metal welded across the front of the front of the spring eye on the driver front spring, front hanger. Does it have a piece of metal bolted behind the shackle on the drivers front spring? This was a factory ‘72 thing to prevent the spring from coming thru the floor in an accident. Some earlier trucks did have this stuff added in a recall if I remember correctly.