is it possible to swap a 74-81 bumper for a 70-73 bumper? (front) Would i have to replace quarter panels and hood also? will it fit?

You can swap the front bumpers, but you need to change the front fenders and valance to make it look like a 70-73. Along with the radaitor sapport is different and need it out of a 70-73 camaro. But it will a bolt right on to a 74-and up camaro.

Why would you bother. Just buy a 70-73 camaro. Good luck and please dont do it. if you do than it will drop the value significantly.