I have been told by one 87 GN owner that he was going to change his speedometer gear. It is the little colored gear on the end of the speedo cable that enters the transmission that you change if you put in a more or less rear axel ratio so the speedo reads right. He said that he changed it to a 2:09 (it might have been 2:29) ratio gear so the speedometer would read in KM/hour but he would know it was mph. It would change it into a 160 mph speedometer. He had to remember to use the correct number scale. He said that 3.42 multiplied by 100/160 is about 2.13 -- (2.09 or 2.29) was a GM number before overdrive.
Of course this would mean that for every 100 miles on the odometer, there are 160 in real life. I wonder how many "low mileage" GN's are out there that have more real miles?
Can this be done? I am thinking about doing this if I get a new chip. If you know, what is the gear color?
As an aside, I bought a 1960 Pontiac that was shipped with a 4:11 gear in 1966. When crude oil doubled in 1959-1960, drivers went nuts. There was the Mobilgas enonomy run, et. al.
The previous owner changed the rear end to a ~3.09 and the speedometer was way low. At an indicated 30 it was going over 40 mph. I guess the odometer was low too.
Of course this would mean that for every 100 miles on the odometer, there are 160 in real life. I wonder how many "low mileage" GN's are out there that have more real miles?
Can this be done? I am thinking about doing this if I get a new chip. If you know, what is the gear color?
As an aside, I bought a 1960 Pontiac that was shipped with a 4:11 gear in 1966. When crude oil doubled in 1959-1960, drivers went nuts. There was the Mobilgas enonomy run, et. al.
The previous owner changed the rear end to a ~3.09 and the speedometer was way low. At an indicated 30 it was going over 40 mph. I guess the odometer was low too.