A friend of mine made one for an LS1 using a PIC processor. It used a couple of stock haness connectors, and plugged into the ignition harness. It basically had ignition pulses as its input and output, and if the frequencies indicated that a certain cutoff rpm had been attained, it would take out some timing until the target RPM was reached. Simple control system, programmed in assembly and burned to the PIC. Only the chip and a few supporting components were needed on the board. Should be even easier with your engine.
Wes
