More Disc brake swap questions

1. Yes, use the adjusters to take tension off the torsion bars. Otherwise the suspension will unload when you break the taper loose on the ball joints, and that can be violent depending on how much tension is on the bars. Regardless, you'll have to loosen the adjusters to put the suspension back together. You don't need to pull the bars out of the sockets if you back the adjusters all the way out, but sometimes it can make it easier to put things back together.

2. ***edit*** sorry, I may have messed this up. The tie rod ends on a '66 are a different part number. Not sure if it's the taper for the ball joint that's different, I'll have to check.

3. The manual push rod in there now should be fine. There are different lengths for manual and power, not disk vs drum.

4. The center register on drum wheels is smaller than on disk wheels, so yes, if you have drum wheels now you will need later disk wheels with the larger register to fit over the disk hub.