Tachometer calibration

[bfiakas]

I installed a newer instrument cluster I got out of an 88 B2 Eddie B. which had a automatic tramsmision and mine is a manual.Before the install the idle was 850 rpm an after it's now reading 1050 rpm. Is there any cailbration to do and if so how do you do it?I checked the actual rpm at the coil with my Sunpro tach which is 850 rpm.

 

[adsm08]

What was the purpose of the cluster swap? It may be that the "new" tach is bad.

 

[bfiakas]

The old speedo was sticking and pulsating.I can live with the rpm differance since I know what the actual rpm is.The newer instrument cluster has a fresher look and I only paid $15 bucks for it at the junk yard.