Holley Projection fuel injection system. This is the early analog system that relies on input from the TPS (Throttle Position Sensor) and your tuning of 5 dials on the controller. Works with big blocks or small blocks just by flipping a switch one way or the other. If you want to read about it, the manual for it can be found online at: http://meb.bronco.com/techinfo/references/projection/projection2.html Add a TBI fuel pump of your choice and it's ready to hit the trails. /forums/images/graemlins/cool.gif $300 plus shipping from 80919.