they are the same chassis, but the monte has an extended wheelbase. the monte has a few more braces,and a steering stabilizer on the center link like a 4wd truck. everything suspension related is interchangeable, i believe.
they don't have leaf springs in the rear, they are a 4 link suspension.
i have had a few mid 70's montes, and i like them a lot. my favorite car, actually.
1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16" IROC wheels