Dont swap the flexplate, dremel the one you have to fit the smaller TC. I suggest against the HD upgrade.

Swapping the PCM for a GTP is a BAD idea. The best method of top swap is to use a GT file, DONT swap the map sensors (use the 1 bar), and adjust a few of the fueling tables to work with boost a bit better.

ZERO wiring changes are required, run the BBV in stupid mode (hook non boosted vacumn to the top of the valve, leave the bottom open) and it works the same as stock.