I've mostly worked out everything that needs to be done for the engine swap. How to route the radiator hoses is the trickiest problem so far.
The most exciting part is finding a MAF sensor that I can use. http://en.wikipedia.org/wiki/Mass_flow_sensor#Hot_wire_sensor_.28MAF.29 I've taken it from a '96 Ford Laser. The same sensor is also fitted to Mazda MPVs. Since they have a bigger 2.5L V6 engine, I expect the sensor to cope well with large air volumes.
I'd check to see if blowing through the sensor would cause any measurable change in voltage on the wire that was being probed. Eventually I found the right combination for the hot wire. The response was initially very slow, but became faster after blasting it with a leaf blower. I guess the dirt added some thermal mass? Or maybe it was acting like an insulator?
Either way, an ADC working on the right voltage range should be all I need to read the signal :) Now, does anyone have any suggestions on how to properly clean a MAF sensor?