What where the main differences between the '71 and '72 Demon?

We are going to see about making a deal on a 4-speed 340 '72 Demon roller/parts to put it back together and would like to start understanding these cars. Looking at parts there are a lot more for the '71 (like front bumper says '71 what is different on the '72?). What were the main differences between these model years?

Thanks,
Jim