Contenu
The big block Cadillac is one of the biggest and most underrated V-8 engines ever produced. Although this may have something to do with the fact that Cadillacs so equipped were expensive and unlikely to be torn apart, it probably has a lot more to do with the lack of aftermarket support for these amazing behemoths. With 500+ cubic inches, earth-moving torque and potentially similar weight to traditional 350s, why more people do not build them borders on the ridiculous.
Crankshaft
The simplest and cheapest way to bring your Cadillac 500 or 472 up to its full potential is also probably the most distasteful to Caddy enthusiasts. Big block Chevy parts are plentiful, cheap and race-tested and are an easy fit after a little machining. The Caddy crankshaft has more than enough material to have it off-set ground to .300 smaller than its original diameter. Off-set grinding moves the center of the crankshaft rod pins outward, effectively making the crankshafts arms longer. Machining the crank in this way will get you another 35 cubic inches; combined with an .030 overbore, that gives you 40 more cubes for a total of 540.
Rods
With the crank throws machined, you can now utilize any one of several 6.800-inch Chevy H-beam rods. Callies Compstar H-Beams are bullet-proof and will keep your engine safe above 5,000 RPM (the point at which your stock rods will break). Other options are Eagle ESP rods or Howards Billet Steel. Whatever you do, stay away from those trick full-race aluminum rods that are commonly used in big block Chevys. Theyre overkill for the RPM range youll be looking at and are really no stronger.
Heads
You can use your engines original heads, but theres a lot of power to be had by using small-chamber 1974-76 heads with 2.19 inch intake and 1.84 inch exhaust Chevy valves. The heads will need some porting work around the bowl area and push-rod pinch. When doing the port work, it might help to think of the big Caddy as you might a diesel engine; theyre designed to pull, not rev. If youre building an all-out race engine, consider replacing your stock iron heads with Bulldog aluminum heads. A really good set of stock ported heads can support over 700 horsepower (naturally aspirated), but aluminum heads will shed over 100 pounds from your engine. Combine those heads with an aluminum Edelbrock Performer intake and a set of headers, and youll be looking at an axis-of-the-Earth-shifting, 540 cubic inch big block that actually weighs less than an iron-headed 350 small block.
