OMG! I'm looking for some tach knowledge

[bilfman]

Hey crew,

I am a stubborn old wrencher and usually beat my head senseless working through truck problems, usually the fix comes My recently redone 79 dually had many electrical gremlins to work through, gauges, lights, wipers, washer heater, got them all figured out. PITA stuff. Anyhow, now that the 'sex machine' is on the road it appears that the factory tach is out quite a bit, I would assume about 1000 rpm.

I have total faith in this site and only found it a few months back, I am now addicted and enter daily. I figured that I would just tap this wealth of knowledge for a starting point. So here is my question. Has anyone had experience with the factory tach? Is there any way to recalibrate or adjust it? I'm going to pull a spare aftermarket one that I have and just 'lay on the seat mount' to see how much the factory one is out, then take it from there.

My buddy and I tried the drinking a case of beer and staring at it last night, didn't work......now on to plan B

Thanx peeps!