how much horse power does a chevy 283 small block put out with .40 over pistons?

Answer 1

To many variables to figure out.

Carb
Exhaust
Condition of the motor.....etc

ONE HORSEPOWER PER SQUARE INCH
For a long time, one horsepower per cubic inch (of displacement) was the unobtainable goal. A milestone to be pondered: "Wouldn't it be cool to get a horse per inch?" Today, reaching that level is a fairly simple task (although few production cars make it there). With simple bolt-on's from the performance aftermarket, enthusiasts can achieve well in excess of one horse per cubic inch. Super Chevy magazine has built engines that churn out horsepower three times the displacement numbers.

Chevrolet first hit the one-horsepower per-cubic-inch level in 1957. The 283 small block was fitted with Rochester mechanical fuel injection (called "Ramjet injection") and churned out an impressive 283 ponies (a number that grew to 290 the following year). Unfortunately, though, Chrysler beat Chevy to the punch by making a whopping 355 horsepower with its 354 cubic-inch Hemi a year before.

Answer 2

I had a 327 with a 230/480 Bracket cam and 2.02 heads I never drag raced "legally" with it but it would run neck and neck with a LS1 camaro this was in a 69 chevelle wich was 500 lbs lighter. Those make 330 at the rear wheels. I would say with the extra cubes and the extra durations it should be close to a 400 HP engine at the crank. Then figure 15-20 percent drivetrain loss to the wheels if its a auto car.

Answer 3

That depends upon many factors. If there are no other mods, a .40 overbore isn't worth much more than a couple of HP.