I recently bought a truck and the previous owner said it had a 305. I was just trying to verify it were true or not. I found the cast block #, which is 3970010. I couldn't find anything else. Least for the time being. I do know the time key is behind the water pump. (12:00). Ive heard that all 350's key tab is at 1:30 position, which makes me believe its a 305. I'm just trying to find out exactly what I have. Help would be appreciated!