Hi Dogface,

I followed Cmayna's suggestion on a previous post and called Jim at PATC, 888-877-1008. He wanted speedo reading when the true speed was 40, 50 and 60. Had to get Speedbox app or my iPhone, which showed correct speed. Adaptor cost $79, but easy to install and speedo is right on now.

I initially got the wrong one, too! Didnt have to do calculations, but I still got it wrong. I had given him true speeds when the speedo read 40, 50 and 60. Sent it back and he rebuilt it. Only additional cost was shipping. Sure is nice to have speedo showing correct speed.

Bob

1959 Chevy Apache Short Bed Step Side
1967 Cadillac DeVille Convertible
1967 Pontiac Firebird Convertible