[Tx Firefighter]

You should be able to unbolt the 71-72 front end and bolt a 63-70 drum brake front end right back on. You can use powersteering box too. Some of the 67 model trucks didn't have the frame dimple for the power steering box, but your 68 should have it.

Factory drum trucks used a splitter junction that looks similar to a proportioning valve, mounted below the master cylinder. They should be fre for the asking in the parts board. Most guys, myself included just throw them away when swapping to discs.

Respectfully, I'd recomend a pair of 6 lug front brake rotors. That way, you can run stock looking 6 lug wheels, but still keep the disc brakes and not have to change any front end stuff other than the rotors themselves. You'd be the only one who knew your truck had disc brakes, and it will sure stop better than the drums would.