Calibrating tach when switching to 155mph speedo?

I know this has been mentioned many times before, but I can't find the answer I'm looking for using the search feature.

If I swap out my 120mph cluster for a 155mph cluster, the actual speedometer will read correctly, right? But the tachometer will be off, right? How do I get it to read like a V6? I remember somebody mentioning that all that has to be done is to put a small capacitor or resistor in-line somewhere and it will read correctly. I know Dakota Digital has an adaptor but if I can save some $$$ I would like to. Anyone have any other ideas?:confused:

The Hypertech 3 claims to re-calibrate everything from gear ratios to speedometers to rim changes. Check into it, it might handle the tach too.

That is, if you don't mind dishing out $300+ :)

Originally posted by ibanez6rg
That is, if you don't mind dishing out $300+ :)
And I do mind!;) I have heard there is a simple way of doing it.... just can't remember exactly.

Originally posted by firebirdude
And I do mind!;) I have heard there is a simple way of doing it.... just can't remember exactly.

Well then good luck to ya! :D:)