All these supercars were under-rated for the same reasons....

A lot of High-performance cars have their horsepower ratings grossly under-rated by the manufacturers. This was usually done for three reasons-( 1) To make the cars dominant in stock class drag racing, ( 2) To avoid the wrath of the safety Nazis, and ( 3 ) To avoid high insurance premiums. As early as 1966 activists like Ralph Nadar were demonizing musclecars and insurance companies were exorbitantly raising the rates on cars with engines over 400 cubic inches and hp ratings over 300 hp. Here's some classic examples # 1. Boss 302 Mustang / Z/28 Camaro. The 290 hp ratings that both Chevy and Ford had for these cars is laughable. The Trans-Am racers run by Mark Donohue,and Parnelli Jones and others had about 460 hp; and except for headers and maybe a little more cam, they weren't that far from stock. Think of this-the 11:1 302 Chevy with Corvette "Fuelie" heads, a hot solid-lifter cam,an aluminum high-rise intake and a 780 Holley , makes 5 hp LESS than a standard headed, 10:1, "station wagon" hydraulic cammed, iron intake with a Quadrajet 350?  The Boss 302 with "Cleveland" heads having ports and valves the size of a 427 Chevy,a hot solid-lifter cam, an aluminum intake with a 780 Holley and special exhaust manifolds only makes the same hp as the "station wagon", hydraulic-cammed, iron intake with a 470 cfm Autolite 4300 carbed 351W?  Really? These engines were making 350 hp off the showroom floor, easily. # 2. Ram Air IV 400 Pontiac. The 370 hp rating for this engine is utterly ridiculous. Especially since the "big car" 400 that was the GTO's standard engine was rated at 350 and the RAIII which had a bigger cam over the base model and Ram Air induction was rated at 366. Pontiac engineers want us to believe that completely new cylinder heads with round port exhausts and iron headers, a hot cam with .520 lift and a special valvetrain with longer valves, and pushrods and dual springs, and an aluminum high-rise intake is only worth 4 hp over the standard D-port headed, iron intaked, .414 lift cammed RAIII?  That's why in drag testing they usually ran within 1/10th of the vaunted LS6 Chevelles-because in the same weight car-they had 80 hp less!!  Riigghht. # 3. 428CJ Ford. This one takes real balls. 38 extra cubes, 427 style heads,a hot cam, and a 735 cfm Holley on an aluminum or iron "Police Interceptor" intake is only worth 15 hp over the standard LTD / Station Wagon / Pickup 390?  That's the story Ford was selling and they stuck to it all years of production. The "generic" 390 was rated at 320 hp; the 428CJ with nearly 40 extra cubes and all those go-fast goodies only had 335?  Puhleeze. # 4. L88 427 Chevy. You belive that the 12.5:1 compression, rectangular port headed, solid-lifter cammed, aluminum intaked, 830 Holley carbed L88 only made 430 hp, when the 10:1, oval-port headed,hydraulic cammed, iron intake with a Quadrajet 427 that was optional in "big cars" and the standard big-block in the 'Vette was rated at 390?  Or that it had 5 hp LESS than the 11:1, smaller cammed, tri-power L72 / L89??  Evryone knows the L88 was putting out at least 500 hp if it made an ounce!!  # 5. "W31" Olds 350. I touched on this one in a previous post. The standard Olds 350 4bbl has 310 hp; Olds wants us to believe that heads with bigger valves, special exhaust manifolds, an aluminum high-rise intake and a 308 degree cam are only worth 15 hp over the base engine?  And require a 4-speed and 3.90:1 or 4.33:1 gears!!   #6. 1985-87 Buick Grand National. Do you honestly believe a 3,600 lb car can run high 13s in the 1/4 off the showroom floor with only 245 hp?  Like Ditka says-"Come on,Man!!"  GNs were making at least 350 hp; GM just didn't want to say it publicly and ire the insurance companies and the safety Nazis. Think-the LB9 TPI 305 in the IROC-Z was rated at 230 hp, and they could only run low 15s. 15 hp can drop a full second off the 1/4 time?  If you believe that-like George Strait says-"Ive got some oceanfront property in Arizona.."  I'm sure I overlooked a few-the 340 Six-Pack only had 290 hp, when the 4bbls had 275?  The L78 396, which had the same heads, cam, carb and intake, etc as the vaunted 450 hp LS6 454 didn't have 400+ hp but only 375? When the oval port, hydraulic-cammed, Q-jet equipped base model L34 had 350?  Anyhow, you have to take the ratings with a grain of salt and look at the performance figures. Mastermind