How many cubic inches was the Pontiac astra engine?

There's no Pontiac Astra. Pontiac was a General Motors brand that used various engine sizes. The Vauxhall Astra, sold in some markets outside North America, used a variety of engines from different manufacturers and sizes over the years, none typically described in cubic inches (a US measurement). Cubic centimeters (cc) or liters (l) were usually the measurements used.