There was a factory option 125 amp alternator for early 318 Magnums. I put one in my '92 Ramcharger (since I'd put a big stereo and bigger CB in it), which was the first year for the Magnum, so I suspect the same will work with your '94 (both are OBD-1). Mine also had an original factory 90 amp alternator. I did hafta swap the pulleys, but otherwise, it was a perfect fit. Advance Auto can get them - you might even luck into a local one that has one in stock. I am not familiar with a 136 amp MOPAR alternator.