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Speedometer Connection?


New member
Nov 29, 2023
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I just had a 1987 350TPI motor put in my 1986 Trans Am.

It was upgraded from 305TPI, which was locked up.

It runs great, but the speedometer does not indicate MPH.

I am just looking for suggestions on where to look first for proper hookups.

My car has a digital dash installed, which had some other issues but always showed the speed correctly.

Does anyone know of a company that still repairs the digital instrument panels?

The motor I used came from a 1987 Trans Am that had been totaled.

Luckily, it did not damage the motor.

The motor has been modified, but I do not know what was altered besides putting a Holly intake on it.

I believe the heads were changed because the mounting bolts for valve covers were in the center of the valve cover, not on the sides.

Is there any way to tell which heads may have been used?