Here's another question that shows how little I know:

Does the speedometer register from the front or rear wheels?
As we'll be changing the tire size (diameter) I'd like to figure how much it will effect the speedometer's accuracy.

Don't want my kid getting any (extra) speeding tickets!
Thanks

It registers from the transmission, making it the rear wheels. You can try and see if a tranny shop in your area can help you determine which gear to change to match the speedo. The gear is I think where the speedo connects on the tranny. I didn't change the speedo gear when I swapped in a TH400 and got a speeding ticket first day driving it.

just how big (or small) from stock do you intend to go?

just how big (or small) from stock do you intend to go?

Here you go!!! (http://www.700r4.com/speedoCalc/speedocalc.shtml)

NOTE: This is for a 700R4 trans which your Caprice should have as an '83.

nice calculator - once you get your tooth count, visit the dealer for the correct gear.