Tach capacitor for V8

Which capacitor on the factory dash assembly do I change, and to what,
to count appropriate pulses for a V-8 swap? 1990 760 Turbo

Forrest

 

I've heard of this before as well but, everywhere I've checked no one
seems to be able to help.
As far as I know you need a tach from an '82 '83 six cylinder which has
a potentiometer on the back side which needs to be turned all the way to
the left position. I've not been able to get my hands on one of these
either.
If anyone knows where such an animal can be obtained please
respond....... I'd be greatful
Herman '83 282 5.0 H.O. formerly 242 Turbo intercooled

 

Back when Car & Driver did an article on Mr. Converse and his Volvo
conversions, they mentioned it, but not specifically!

 

It should be easy to find by looking at the circuit, I haven't paid much
attention to how the tach works but I'm guessing it's a fairly simple
frequency to voltage converter.

 

I think that it needed a change of resistor, not capacitor.

Does this also apply to 82-83 264/265 dashes? I'm intending to swap
an '82 dash into my '80 model and haven't done anything yet about
recalibrating the tacho. Haven't started pulling the donor 265
apart yet...