87-89 Ford Mustang 4cyl Tachometer recalibration for use with 5.0

[@sarahbyrdziak7343]

Wow. Great informative video. Any chance you know what resistor to change on a 1985 tach? I want to put the svo 4cyl cluster into my v8 and would love to figure this out.

[@Mustang5L5]

I do not what what resistor size for the pre-87 cars? But I was under the impression that the earlier tachs had a 4-6-8 selector on them to choose engine size. I could be wrong on that. Have you taken a look?

[@Fredness2300]

1989 2.3L 4cyl 6K tach, installing a v8 7k tach as the 2.3L is built, and balanced to run over 7k. Would you have any input on going the opposite direction?

[@Mustang5L5]

@@Fredness2300 unfortunately I wouldn’t be able to quote a resistor value to go the opposite direction. I’d have to play around with it on a bench. Logically you would assume that you can just measure the resistor on the 6k tach and install one on the 7k tach but I found the values to differ slightly. I’d had to set it up on a bench and play around with the frequency generator and a variable resistor installed to figure out a starting point. Not sure if I can actually get to this anytime soon

[@1calvin]

I noticed the needle on the 4 is bigger than the 8 do you know why? Thanks for the video.

[@Mustang5L5]

The needles are the same. One of them has had the white indicator paint removed so it just looks different. In hand they are identical. I’ve swapped needles around a bit so not sure which needle was originally on what tach.