Will a 1.6 16 valve fit in a 1991 Geo Tracker?

Yes, a 1.6-liter 16-valve engine can fit in a 1991 Geo Tracker, as this model originally came equipped with a similar engine type. However, compatibility may depend on specific details such as engine mounts, wiring harnesses, and transmission compatibility. It's advisable to consult with a mechanic or perform thorough research to ensure a proper installation.