The original clock housing requires 3 small holes for the studs and 1 larger hole for the lamp socket to be cut or drilled into the dash. Once you make those holes, there's no turning back. The picture is not my truck but the clock housing (tachometer installed) looks good when viewed from the front, through the steering wheel. When viewed from the sides, I can't help thinking about a cyclops with one eye sticking out. Obviously I'm old school and I prefer a plain dash. My point is, be sure that this is what you want before making the dash holes.
What is the purpose of having a tachometer in an old stock truck with stock gauges? Your ears can tell you when a Stovebolt engine is being overrevved. Instead, it would be a visual indication on when to shift gears (shift points). If I remember correctly, the old VWs had small marks on the speedometer dial to tell you when to shift or a shift before this point.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
