69 gmc to 72 disc

[pbro]

I’m finishing up a disc upgrade to my 69 gmc with hydroboste. I got two questions that I need some guidance:

1. Do I need a new porporting for the disc brakes or can I use the existing?
1.a. If I need a new porporting do I need to run 2 new front lines as the old hydroboste had one line out of the porporting to both front from a Y junction.

2. Inner tie rod isn’t working for 72 spindle but ordered year specific from rock auto. How tall should the shaft and thread be on the inner?

Any help or advice is greatly appreciated.