When we first started this project, we knew we had to have something other than the factory duraspark controller powering the ignition system. It had failed twice before and left us stranded in the middle of nowhere in the dead of winter. So we did a little searching and came up with the perfect alternative, an ignition system by Jacobs Electronics.
Jacobs offers a simple bolt on replacement that uses the factory duraspark controller and coil for the timing signal and a complete replacement kit that does away with the factory controller. We chose the latter. This meant we could throw away the factory coil and duraspark box!!!
Since we were building from scratch, we decided to mount the Jacobs system in same location as the factory module since we were going to integrate the unit with the main vehicle wiring as much as possible. We started by locating and drilling three holes in the fender liner to mount the Jacobs Electronics Pro Street controller. Once in place we cut the plugs off of the old duraspark box to be grafted onto the Jacobs wiring. Fortunately for us, the colors of the factory wires and the Jacobs wires are nearly identical. We have a magnetic pick-up distributor and the corresponding wires are orange/yellow and purple/light-blue. The Jacobs leads are orange and purple. The tachometer lead from the factory is dark-green/yellow. The tachometer output from Jacobs is green. We simply spliced the matching colors of the old duraspark plug to the Jacobs wiring and connected the wiring harness plugs as if it were a factory installation. At the engine, we trimmed the connectors for the coil and the tach and looped the wires back into the wire loom since they were no longer needed. Lastly, we needed a powered ignition circuit. The second plug from the duraspark gave us just that. By splicing the plug to the red wire of the Jacobs system and making the connection, the installation was complete.
Now we installed the Jacobs Ultra-Coil. We located the coil next to the ignition module for ease of installation and to keep the wiring to a minimum. The white and black wires from the main module were connected to the coil. The last piece of the puzzle was the coil wire to the distributor. The Jacobs kit comes with a universal coil wire and several different style connectors. We measured and cut the wire to length and installed the straight connector on the end. This simply snapped into place on the coil and the installation was complete.
Now we have a high performance ignition without the hassle and worry of the duraspark system. The installation was almost seamless. As you can see from the photos, it's as close to a factory installed appearance as you can get.