I've got a harness built by Current Performance Wiring, left from an old customer. It's a direct swap, maintains all cruise control, AC, and electronics. Plugs into all the factory connections. It's designed for the stock '96 4l60e.

Offhand I don't know what other years/models it would be compatible with, but I'd assume most any 95-99 OBS.

$650 shipped anywhere in the US.