GRAND PRIX Anyone know what this is?

[Gonzo1970]

200-R4 - in line with the speedo cable.

Can't seem to get a good pic of the numbers while its on the ground. Next time its on the lift, I can get better pics, but I figured someone here would know.

Thanks.

-Gonz

 

[melloelky]

it's a speedo correction box,you usually see it on trucks with giant tires to correct the speedometer etc.

 

[Gonzo1970]

Thanks! Weird. Not sure why it would be there. According to the window sticker and build sheet, everything on it is stock.

-Gonz

 

[airboatgreg]

I think it is just a coupler as it does not appear to be large enough to be a reducer. A way to shorten the speed cable and allow the option of cruise control or not. These years of G Bodys had an issue with speedometer needle bounce

 

[565bbchevy]

I have a ratio box on my Monte and though it looks similar the cables are offset and the box is larger to accommodate the gears.

 

[Cutlassman.mw]

It is a calibration box.

 

[69hurstolds]

It's needed to correct the speedometer. There's some numbers stamped in it that show part number and the reduction ratio. Some rear end and transmission combinations came that way from the factory. Sometimes when people change gears/tires they may need one as well.