Hmmm. Even weak springs would not give you 50 degrees all in at 2500 rpm. The 2403 distributors provide between 12-14 degrees of mechanical distributor advance, so 24-28 total at the motor. The total advance is limited by the shape of the weight and the internal mechanism itself. So it may be that the design of the distributor is bad from the get go, or any chance you forgot to disconnect the vacuum advance?
