Rotating stepside Fenders?

[2bits]

Hey guys, I have a 71 stepside that I just put a 73-87 stepside bed on. I am planning on pulling the gas tank from behind the seat in the cab, and installing a Blazer tank in the back between the frame rails. I got this idea that if I pull the fenders off swap sides, the location of the fuel door will be at the back of the driver's side with is a perfect location for the Blazer tank. I can remove and relocate the steps easy enough, but I am wondering if without the step, are the fenders the same front and rear? They look the same to me to where it would work....