95walter

I know this is a very stupid question, but I am building a 306 and I wanted to put gt40p heads on it. My question is I was putting everything together today and I was putting the headers on before I dropped it in the car. I noticed that the spark plugs where facing the front of the motor on the passenger side of the car. My question is that can you put the heads on backwards? I believe that I bought two drivers side heads. I know that this is a dumb question but I have been working on it all day and wanted to see what someone else had to say about it. Thanks