My tach runs up to 4300 then sticks there. After the rpm has come down below this the gauge will eventually as well. As long as I stay below 4300 it seems to work ok, but does seem to be turning high RPM compared to the rebuilt speedo. Other part of question is there another tach that fits nicely and might be orginal and that goes past 6000 ? My 289 has some kinda cam and it winds up really quickly and I’m sure past 6000. I have pulled some info from the tiger board, but now the archives seem to not be working,….cheers…..phil
Generally speaking, most orignal tach mechanisms do not track well. Even when rebuilt by the popular rebuilders. The problem is compounded by the various ignition systems in use today. So if accuracy, tracking and repeatabilty is desired, the mechansims must be upgraded or replaced. There are several options to do this.