I'm changing over to gauge from sweep. Are all 70 - 72 gauges the same? Ive searched and learned that the wiring is different. If I buy a 72 gauge cluster, which wire harness do I use, the 72 or do I use a 70 harness?

The gauge clusters are the same for 70, 71 & 72, except for the color. 70 has light green numbers/lettering. 17 and 72 have white. The dash harness for 70 and 71 are interchangeable,there are some minor differences. The 72 dash harness is way different. It's better to find a 70/71 harness for 70/71 cars and 72 harness for 72 cars.

A 72 harness can be modified. wires moved in the bulkhead connector, to use in 70/71 cars, and a 70/71 harness can also be modified to be used in a 72. When you do this you some circuits will not work like key warning and TCS but are typically not used anyway.

The forward lamp and engine harnesses are year specific.