Haven't done it specifically 60 bird, but this is how I've done it on other swaps.

1. Place the tranny and shifter in park, locate and mark (I usually use a felt tip marker) a point on the tranny shift arm where the shift rod will attach.

2. Place the tranny and shifter in low gear, and see how close to the mark the shift rod rod is.

3. Keep adjusting the mark up or down until you reach the point where both park and low use the same mark. Up (toward the pivot point) if you need more throw and down if you need less.

You may need to either legnth or shorten the shift rod and/or extend the tranny shift arm The rest of the gears should fall into place.

As far as the kick down, you can either use the one that came with your engine/tranny combo or reuse and modify (the tranny end) the birds existing intake mounted bellcrank assembly.