Still related but almost exactly the opposite of the OP's questions, how would you run the factory tach with a diesel swap? Beings there is no ignition signal and only the "w" terminal on the alternator to pull a tach signal from, I'm lost. Any ideas? I'm planning a VW turbo diesel swap this coming winter with a Toyota trans and case, Acme adapter, and the tach and speedo are two major obstacles I'm looking at. Using the factory gauges and idiot lights has become a priority beings my GF will be driving the car from time to time.

'97 Sporty, 4wd/MT- Mazda/Aisin manual hubs, ghetto cold air intake. Planning- Mechanical OD auto/Dana 300 swap, SAS, and a little tooob...