Cadillac built one of the first powerful V8s, and then Chevrolet created the best power to weight V8 going, stealing from Cadillac the heart of performance. Now I had a 1973 Coupe Deville with 472, it could move good for a landward aircraft carrier, and one could transplant that into something of lesser tonnage, but a 327 likely gets you there on way less pounds in the nose.
IIRC, the '70s Cads were, in fact, lighter than the (smaller-CID) SBCs. The late '50s & early '60s Cads were beyond question lighter than the boat anchor Nailheads & Rockets.
In the '70s, the lightest thing around, except for the aluminum Buicks & Oldses (& Rover clones), were the Buicks: the 425 & 455 were lighter than the Chevy 400s, & the 350 Buick easily lighter than the 327 & 350 Chevy. (IIRC, the 350 Buick was less than the 283.)
Either way, that 500 Cad in a Malibu/clone (let alone a Nova!) would blow away just about anything, except (maybe) a 455 Buick-engined version--&, IIRC, the 455 wouldn't always fit between the shock towers; the Cad would drop in place of a 350 SBC. (The 455 had more torque than anything much short of a railway locomotive...

The 500 was pretty close.)
Me, I'd have punched out a 215 Buick to 305 & stuffed it in a Morris Minor.
All of which is getting way, way off topic...