1972 Mercury Comet

I purchased this car in '04 from a local auto wreckers for $400,the car was basically all there except for the starter & exterior mirror.It has rust in the rear quarters, fenders and drivers side torque box and rear passengers side roof.But i do have a plan for this car i have a 302 2v i'd like to swap out the 1v 200 i6. This car came with staggered rear shocks witch is weird for an inline six car (My 70 torino GT ( m code) didn't even come with that),but i'd would like to fix the rust and get the motor & trans in there and get this comet on the road , but a big part of me thinks it aint gonna be that ez!!