Kmurph,
Since my speedo hasn't worked for years, I installed a tach just a week ago in my '50
chevy (12 volts). Went to a local Pep Boys store and bought the smallest tach (2-1/4" dia) I could find (Brand name of Actron). Had it installed in 30 minutes.
4 wires (Ground, hot after switch is on, light & neg side of coil).
I've always wanted to know the RPM's and now I know. Had my wife follow me to tell me how fast I was going and I noted the rpm's. As soon as I can confirm what gears I
have in my rearend, I can then calculate the different speeds per different rpm.
My 235 seems to run its best at just over 2,000 rpm. I'm gun shy to take it beyond 2,500.
