Speedometer

Trying to figure out why speedometer doesn't work. 1972 dodge demon 4 speed. Dash needle moves when cable is turned by transmission. Cable has good fit into mount at transmission. Pulled gear out of transmission, and it looks good. Noticed numbers on gear shaft housing AFTER I took it out. They are evidently for correct positioning of housing so gears will mesh. My question is where numbers positioned when installed for correct fit.?
Speedo Gear is 37 tooth, rear is 3.55 , tires are 245-60 r14. Do I need a different gear to be more accurate?