Would it be viable to swap the front & back metal bumpers from a 1974-1977 camaro onto a 1980 camaro without major body work?

 

You can do it but the only thing you'd keep on the front end would be the hood and radiator support to get the bumper to work and fit. In back 75 to 81 quarters are the same. To change the rear bumper though you'd have to cut out the old rear body panel and weld in a 74-77 panel. Feel good for yourself that you don't have to change quarters as changing the rear panel isnt THAT much of a big deal if you are 1/4 decent welder.

If you have sheet metal from a donor or just fell like plunking down cash for new parts it can be done.

 

So on the front end I would need to replace:

~ Left and Right front fenders
~ front nose
* would I have to weld the front metal bumper in place or is it attached to the front nose itself?

 

The metal bumper is attached with brackets to the frame. Yes, left and right fenders and nose assy. Hood is the same. Inner fenderwells will interchange.