No adapters required.
Add one extra wire from the LS temp sensor location, connected to the OE dash gauge, and install the 3 wire sensor and pigtail for a 1998 V8 Camaro. The cost is about $30 for the set, and it replaces the stock LS temp sensor in the cylinder head.
Installation is a snap. Two wires connect exactly as the original LS sensor, and are positioned the same in the connector. They feed the ECM a 5v loop. A third pin is for the dash gauge. It is the usual variable resistance to ground, through the sensor body.

The part numbers are:
Sensor- 12551708, tx111, or tu280
Pigtail- pt2319, s619, or 1p1065