The turbo does not care if the car is gas or diesel.... it only know to blow air in response to being driven with air. The usefulness would depend on the pressure/flow curve. As above, any low RPM, small to moderate displacement application should be able to use this turbo. The /6 would be a good candidate for low-mid RPM's but any larger displacement V8 would have too much WOT displacement for this to support. A 318/340 range engine would be better off normally aspirated than with this turbo, IMO; the same or more HP and no lag.
BTW, the max boost on this year is pretty good (high 20's). The advantage is in the quick spool-up, which would be a great advantage for something like road racing or rally but of no real use for drag racing. I believe the harness is for the electronically controlled wastegate; that might be of interest with a switch or control on the dash; you could have a 2 way switch on a control marked "Safe Mode' and 'Will It Blow Up Mode'....LOL