How can i find out what size my transmission is?

Hi i have 1989 firebird formula 350 as you can see i dont know much about cars with all my questions but i want to learn so whoever and whenever i can i ask away..thanks in advance..how can i find out what kind of transmission i have in my car..i already got the code for motor which is the 8th number in the vin which was an 8 so i know its a 5.7 but can you tell the from the vin number if not how do can i tell..thank you