My 1993 z28 3.4L V6 Chevy Camaro needs coolant, which one should I buy??

Ethylene glycol.

Same color that was in it before. Don't mix. Green or DexCool. BTW, never seen a Z28 with a 3.4, must be rare.

You see any coolant leaks???.... WHY it's low on coolant may be more of a concern!!