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SERE · 07-20-2005, 01:51 AM

I have adjusted two of them now. It is hit and miss. I used a rpm caculator I found on google and wrote down RPM at 55 60 65 70, Then went for a drive with my GPS on the dash. I was able to figure out my speedometer convsion I needed and if the tach was reading accuratly. I turned that dial at an idle and got it close. Then repeated the process. It worked for me. I have never found it in any manuals, I found the info on this board last year.

Good Luck!

Steve

07-20-2005, 01:51 AM	#3
SERE "AIRBORNE" Join Date: Oct 2004 Location: Spokane WA Posts: 60	tach dash I have adjusted two of them now. It is hit and miss. I used a rpm caculator I found on google and wrote down RPM at 55 60 65 70, Then went for a drive with my GPS on the dash. I was able to figure out my speedometer convsion I needed and if the tach was reading accuratly. I turned that dial at an idle and got it close. Then repeated the process. It worked for me. I have never found it in any manuals, I found the info on this board last year. Good Luck! Steve __________________ 69 GMC 2500 4X4 long stepside 454 BB