FYI - Dennis Olthoff now has a fix for the SPF GT40 speedo error. The error is caused by the fact that the RBT/ZF does not have the proper drive gear and to date, Mr. Butafoy has been unable or unwilling to deal with that. Be that as it may be, Olthoff has built a gear reduction unit that mounts on the trans and the cable connects to it. No need for any other mods. DO claims .01% accuracy. Cost is $95. For those of you that may not be aware, the RBT/ZF trans causes the speedo to read about 22 mph high.
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