I ran one on my '90 3.0 back in '94, the MSD cpu didn't interface well with the oem cpu. First the tach stopped working, than the engine would cut off while running. I sold the set-up to a friend for his '86 22r and it worked as claimed. I switched to the Jacob's unit in '95 and haven't had any problems with it and the oem cpu. I don't know what the 1/4 mile time is between the Jacob's and stock, but I do get about 2 mpg's better, better throttle response and lower emissions using the Jacob's than w/o. If the MSD is still not a direct plug in(like it was), I would go with the Jacob's unit, no cutting or splicing needed, and if a component fails it is easy to hook the oem back up.