Was once given free of charge from a certain guy a Cadillac DeVille two door with a 500 incher in the nest. Weighed at least 5000 Lbs wet. That thing, without any fanfare or exaggeration would lay down a patch of rubber 3/4 of a NYC block without a sweat gland opening. Was having many guys looking like they all had hair lice all over the neighborhood as to why it had so much torque. I can imagine that very same set up as is from the factory or with some CPP heads, Edelbrock intake and some cast iron high flow exhaust manifolds in a 3000 Lbs coupe.
My 68 'only' has the 472... but a high compression one (Caddy guys peg actual around 9.5ish). Its got dual exhaust (not a good one, press-bent 2.5" with ancient Flowmasters), and open element air cleaner, all non-basic options removed (AC, CC, etc.). Its in an honest to god 6000lb car (hearse) and i tell ya... that sucker can get out ov its own way! Even with the 31" mud tires i have on the back, it'll roast 'em both easily. I've got an Edelbrock intake for it and i'm going to build a real dual exhaust. If i ever start spending money in it, first stop is a BIG cam. If i just FIXED what was wrong with this car it would pick up seriously. I couldn't imagine this plant in my old 3200lb Skylark...
Caddy's came with a [censored] tune, restrictive air cleaners and the worst exhaust and intake imaginable. Just fix the first three and you've got something. Actually put a real intake on there, and a cam... ANY cam (just like Mopars, Caddy's came with ridiculously mild cams) and you've got a killer. Spend just a bit on some rockers so you can rev it to 5000rpm and well...
Coolest thing about Caddy's is the block. These things are stout. You can overbore them a LOT. The cranks also have massive rod journals, and though cast, are plenty strong, so you can offset grind them a LOT.
