I just picked up an 86 IROC, it's a fairly late 86, has the 145 MPH speedometer.

Anyways, I plan on swapping in an LT1/T56 drivetrain into the car, and I want to preserve that setups 100% electronic speedometer capabilities. I can easily calibrate that for gears and tires when I flash the PCM to tune the car.

Is the speedometer in the 86 electronic or cable driven? I assume it's cable driven, but to be honest, I kinda like how it looks. I know that newer IROC's had the same looking speedometer, but was there a functional change at some point where it became electrical?

 

Look inside the engine bay down below the power booster. If it is cable driven, there will be a cable connection there with the cable from the tranny connecting to the cable for the speedo.

 

82-89 camaros were cable driven, 90-92 had electric speedos, but the style of the dash and gauges changed in 1990 aswell.

82-85 firebirds had cable driven speedos, 86-92s had electric speedos

 

So then my only choice really is going to be either a complete dash change or an adapter for my T56...alrighty, thank you guys.