I have been trying to figure out what size engine is in my car. No numbers on front of block. No numbers on back of block. Number on manifold is GM 14101074. Don't know if this number tells anyone anything. Tag on carb says 305 4bl. So thats what "was" in it. Car is a 1987 Firebird built in 12/86. 1987 car but has brake light on top of back window.(supposedly 87 has built in spoiler). Also front end HAS been replaced.

 

It's not easy to see, but the number you need is the block casting # which is located on the top of the bellhousing casting to the driver's side.

They often have "5.0l" or "5.7l" for 305 or 350, respectively, there as well.

 

Someone went to lengths to remove VIN #. God knows what is in there now. I am going to change to 350 soon anyway. Just so I can say I have a 350 in it.