the K jet metering head measures air flow and dishes out fuel according to the shape of the bowl the flap rests in.
when you do a k jet turbo the turbo is downstream of the metering head so air is flowing through the metering head at atmosperic pressure then getting compressed by the turbo and presented to the throttel body. the KR metering head can be used if it's fetteld but all out max is 220 bhp and then you are askign to melt stuff, so you use a saab or volvo metering head and injectors and a few other bits of pipework.
it's a very nasty system tho as effectivly you have a 1D fuel map fuel injected v's airflow so lots of throttel low rpm and light throttel high rpm = roughly the same thing so there a bit suseptable to fueling problems and quite thirsty.
ignition is another issue leave the stock ignition system on and it'll go bang. so ether some piggyback box like k star is used to botch it, and aftermarket ignition controller or a reworked 8v dizzy with boost retard is retrofitted to the motor. these dizzys are to be fair NASTY. all in to build a K jet turbo you need tough pistons you have to run the engine richer than you would most of the time compared to the same engine with EFI, and also have to be gentel with bringing the ignition advance in.
all in all it add up to a thirsty engine that just isn't efficent and dosent last very long
