Guys
The TBI injectors are low impedance peak and hold. Microsquirt cannot drive this type of injector. Megasquirt 2 can.
As far as sealing - its no different from the '747 GM controller - both need to reside inside the passenger compartment. Nether are sealed.
Tuning is easy - install a wideband O2 sensor and after you have the engine idling - run autotune.
Once autotune is finished - go to a chassis dyno and do the WOT settings.