Hi just browsing through the reference section and found the 69 schematics manual. Just wondering if there'd be much much difference between 68 and 69, both in schematics and wire colours? Just trying to hook a factory tach back up with a new MSD ignition system, and its all a bit messy back there. Looks like somebody bypassed the factory tach at some point, and installed another on the steering column. Want to see if the factory unit still works before I rip out the sun super tach. Any help much appreciated. Shark.