Speedo repair

I got some real nice repro parts to restore my 1948 Speedo. only problem is that it reads a real high speed, about 74 when I am doing under 40. I was using a Teds 47 Repro and that was always right on, Is there a way to calibrate these better or does taht magnet deal need to be replaced. Parts sat in my garage for 35 years.

Sounds like you have the wrong ratio combination of speedometer and drive gear. There are 1 to 1 and 2 to 1 ratios.