I’ve been bouncing this around in my head but can’t settle on an answer.

If you put bigger than stock tires, or smaller I guess as well, on your vehicle, do you have to adjust your kickdown cable? Meaning my D1’s points are spot on with Rave specs, which are identified by speed ranges. If I’m running my bigger tires my speedo is overstating my real speed but I’m shifting at correct points for stock tires.
Is only the speedo inaccurate? Do I need to get paced and find the incorrect speedo to actual speed differences and adjust the cable to these points? I’m confused....