First off I previously posted the first question in the general forum but got no answers, so....

If you put on bigger tires than stock do you need to adjust your kickdown cable. As Rave specifies setting it between speed points and larger tires will not reflect correct speeds? Meaning do you need to get paced to determine actual speeds vs displayed speeds and adjust the kickdown cable accordingly?

Second, I noticed my tach at idle is displaying around 740 I’d wager but OBD is telling me it’s closer to 640-650. About 100 points off, give or take. Any ideas on which one is likely correct, and ideas on the likely cause? Just an old wearing out gauge perhaps?

The never ending quest to get my boy dialed in...

 

if its a D1 1999 - tach should be 750 ish as I understand.
I have 32's and it actually kicks down a bit sooner - you'll just put your foot in it a bit more with bigger tires. I have not adjusted my KD cable. I have no problems on the freeway or city.