Try Napa or GM Dealer parts. Or any other place that sells or can get Standard Wiring & Connectors or Gates Wiring & Connectors.
Standard part # is S-582 This should be the one on the side on factory carb 82-96 chev all so other list GM"S below. Your wire might be green or black
the comes gray with gray connector.
Buick ............96-93, 91-82
Cadillac .........88-84
Oldsmobile......95, 91-82
Pontiac..........90-82