OldIHC

I've heard ford truck brakes are same as K 1-3 ? If so , which parts will interchange ? Drums ? Shoes ? Wheel cylinders ?

BRJ usually answers this. Brake SHOES are the same as Ferd, I believe.
K-3 (one ton) has "big six" bolt pattern. One rare brake drum. However, it appears that the front spindle is shared with the smaller pickups. You can slide on 1/2 ton (5 on 4.5) front brake drums. You're still stuck with "big six" on the back, though. That will take a rear axle swap to fix.
BRJ will clarify.

KB 1-3 use same brake shoes and cylinders, you can get stainless steel ones from speedway motors rather than from a Ferd supplier,

KB 1-2 use same drums that are now available, I don't think they are same as Ferd, I think it's only the guts that are same,

A KB 3 front axle I beam is beefier than a 1-2 , but spindle/bearing race size is same, so like Monson says you can swap front hub/drums from 5 or 6 lug,

KB 3 6 lug drums are still unobtanium

I will only add that there is an outfit that can re-sleeve the big six drums, as long as they are not to large in diameter. Should be able to find that info on the site with search, my memory is not what it used to be. Myself, I prefer an axle swap, I think it would be cheaper. Just my opinion.

wheel cylinders:

https://www.speedwaymotors.com/1939-48- ... 27708.html

So as far a big six drums go could a guy buy a set of drums with the correct offset/width/diameter and redrill them to fit? They could even be for a wider shoe than stock as long as everything else matched closely enough.

PMS...please show us one instance where this redrilling of brake drums was accomplished successfully. It seems doomed for failure. For something that stays on the farm, maybe. But out on the road? No.
If it was so easy and reliable then everyone short a brake drum would do it.

You remind me of my wife. Nothing is possible. Show me where this has been accomplished unsuccessfully. Gee drums come with holes drilled for the mounting bolts all the time.

I found the link to the fellow who can re-sleeve the big six drum. Here is their web page: https://www.jgrelining.com/services As I said, I personally talked with this fellow and he said he could do the drums.

PMS...we've had "words", before.
Yes or no...redrilling a brake drum is a viable option? Take all the time you need to answer. I work on cars for a living, just the liability of something like that should scare some sense into you. Maybe that's the problem, you have no sense?
As far as your wife and "nothing is possible"...I'm not a marriage counselor.
I routinely do frame swaps but redrilling a brake drum is idiotic. You sound like the dumba$$ newbies who come on here and knock us around about putting little wheels on 1.5 ton axles.
ARE you a NEWBIE?