[Supras] SPEEDO CORRECTION

[robert wilks]

Hello,
      Please put the forum collective mindset on this problem....removed 3.70 lsd....and replace with 4.30 lsd......now speedo reads 15-20 mph fast at highway speeds.    car is automatic trans/turbo.   also ,see the enclosed link.
Hello Dr Jones,
       I have a rebuilt/modified  90 supra turbo......with auto trans.....and a recently installed  4.30 : 1 LSD .
       Problem is, the speedo still thinks the 3.70 LSD is still in service, and therefore, the speedo reads about 15-20 mph fast at highway speeds.
      I special ordered a 'worm gear' (for the speedo cable) for a non-turbo 5-speed manual/sport pack supra......which  originally came from the factory with the 4.30:1 gearing..........IT would'nt fit my trans
      I think the 1JZ  2.5 liter JDM cars were equipped with 4.10 gears, and were available with auto trans.....were they not???    
      Would this be a fix????       would the 4.10 worm gear for one these be close enough correction?
      HELP........you're the doctor....would one of toyota's other JDM models come with the exact worm gear for auto/4.30 applications?
-regards,
bob wilks
205-746-5655
-bob wilks
bobbobtht