With my z31, I skipped the GM HEI, and went straight to the z31 transistor.
The pull-up resistors are still necessary, all they do is "amplify" the signal to a voltage that MS can use.
I added the resistors directly to my 2.2 board, since it was easiest for me. All you do is find the pin on the DB37 (PCB side) that needs the pullup resistor, and find the nearest 12v line.