speedo calibration

[87regalkid]

Hey guys, I was thinking of getting a 145mph speedo insert over my 85mph speedo in my Regal. My question is about recalibration, my speedometer is accurate now, or close enough, but I was just wondering what is done to recalibrate a speedometer.

Is it something that can be done with just the gauge cluster because my case is a conversion, or is the whole car needed for recalibration.

Thanks,

 

[gbondo57]

If you know this, bear with me. A gear, on the trans end of the speedo cable, is based on the axle gears, and stock height of the tires. A dealer parts guy told me that at 65 mph, A 1 tooth count change is worth @ 3 mph of correction. Add gear teeth to speed "up" the speedo, and vice versa. On our 87 Elco/200r4 that turned out well. I'd put it in and go from there. The kit itself should be somewhat correct. Good luck. 8)

 

[Omnivium]

I was wondering the same for the 145mph insert