Firebird Trans am 400 MOTOR VS. 455 MOTOR

[Ruben V]

just by looking at it how can i know if the car has a a firebird 400 engine or a 455 engine

the numbers that the engine have ,do they help any

the motor is taken out and its in a junk yard

 

[1975 ventura]

casting numbers on the block should tell you the year 2bolt main or what there are places on the web you can look it up at