[grendiers]

Don't make it too complicated. Once the car is up and running, after you set the distributor/rotor to match TDC, you can twist the distributor back and forth to set your timing. Using a timing light of course.

As to the timing and an intercooler, there isn't as much of a relationship there, more so though, with adding a manual boost controller to take advantage of the engine management benefits of the intercooler.