Made the other two h-bridge drivers I need (one each for inlet / exhaust VANOS, one for the IAC):
Tied in (just ~tacked for the moment) the radiator mounts to the lower subframe:
The bars running under / beside the radiator is where the lower rad mounting tabs will be mounted. I feel pretty good about the quality of welds I'm getting lately - starting to really get the hang of TIG, I think. Good enough for these jobs, at any rate.
I also realized that the IAC has a +12V input and one input for each of open / close solenoids, vs. the VANOS unit that switches +12V on the solenoid sides and have fixed GND supply. Need to check the WDS to see if the IAC solenoids have bypass diodes; if not, I can just run them backwards but I'll need to install the diodes on the driver. If so, I should also just be able to use the switched grounds on the h-bridge controller for them.
e: WDS confirms that IAC solenoids do not have bypass diodes and that they're expecting low-side switching from the ECU. Bizarre.