First: getting a REAL honest to goodness 500HP out of a pump gas street engine isn't an easy thing to do unless you really know what you are doing (which we do), or unless you are planning on running a supercharger or nitrous.
Second: having 500 HP doesn't mean your car will accelerate or be fast because TORQUE is more important than horsepower in 99% of all street & strip cars. Everything below about 5,200 RPM is all "torque" moving the car. Having 500 HP with 300 Ft Lbs of torque is a recipe for a complete turd of a car unless you have super low gearing, a very high stall converter, and plan on running around at or above 5,000 RPM all day. You'd be much better off having the complete opposite; 300 HP and 500 Ft Lbs of torque. With that, you car will pull taller gears harder, will need much less of a stall converter, will pull more weight (heavier car much easier), it won't require downshifting once or twice to get the revs up into its power making area, and it will literally throw you back in the seat when you mash the gas not much above an idle. THAT is where you will be driving 99% of the time... below 5,000 RPM.
A true 500HP engine will propel a car into the upper 10 second times in the quarter mile (on average - with the right gears, stall, traction, RPM, etc), and really, how many street trim 10 second cars do you see running around? Not many I'll bet. There sure are a lot of people that "claim" they have 500HP, but when they hit the track and run a 14 second et, the excuses start flying like a flock of birds as to why they couldn't pull-off a 10 second, (or even an 11 second) time slip, and the reason they couldn't do it is usually because they ain't really making 500HP, or it may have made 500 HP but again, made no torque.
Third: always remember this, horsepower is cheap, strength costs money. It's a no brainer to pop a set of 13:1 pistons, a large cam, port-out a set of heads and a few other tricks to get a lot of horsepower out of an engine. Horsepower is a no brainer. It's a simple matter of increasing flow going into the engine as well as increasing the cylinder pressure, which can be achieved by increasing the static compression, increasing the flow of the heads & cam, or stuffing more fuel and air into the cylinders via a supercharger, or creating a mass of expansion and heat in the cylinders with a shot of nitrous, which is easy and cheap to do, but will it last? Not if the parts aren't strong enough to handle the stress and heat that 500 HP makes!
Note: To get an even more up-close and personal account on all of this, scroll down the page and watch the two videos I made on this very subject.
The key that needs to be followed is matching the parts so they work together, and building it strong so that it will hold-up under the heat, stress and RPM it's going to be put through. I can easily build a 500 horse small block or even a 750 horse small block for about $2,500 but it ain't going to last but only a few minutes! It must be built with strong parts or it's going to end-up as a large puddle of oil and twisted metal in the middle of the road. Strong, quality parts aren't cheap. There are ads in magazines that offer 350's and even 383 stroker motors with 450 horses (If they really even make that kind of power) for about $3,500, but when you look at what's in them, most of the parts are just crap. They use plain old cast, stock pistons, stock "reconditioned" rods, (which adds nothing to the strength). They use cast iron stock or low priced (and low quality) after market heads, stock cranks, re-used main bolts, head bolts and rod bolts, and so on. Remember this, the ONLY thing holding your engine together are the bolts, so they'd better be the best you can buy! There are too many variables to put a single price on an engine, unless it's a generic "crate motor", and with those, you get what you get, with no choices or options. That's why we don't pre-build any "generic" engines.
Third; when comparing engine prices to horsepower, remeber this, you don't pay for horsepower, you pay for quality and strength! Here's a good comparison. A 750HP small block Chevy Sprint Car engine is about a $15,000 engine. The same 750HP small block in Nascar trim suddenly becomes a $40,000 engine, and they don't even have a $5,000 fuel injection system! So why is the Nascar engine so much more expensive for the same amount of power? That's simple. It's because the Nascar engine is MUCH stronger and lighter.
A Sprint car only has to run a few laps a night, and there's only a little bit of sponsorship money behind the car. A Nascar has to run at 9,000 RPM for 400 or 500 miles at a time with millions and millions of contengency and sponsorship money behind the car, so they can't afford to have a failrue because a part couldn't take the stress. The comparison has the same princibles in ANY engine when comparing prices, including street engines.
Our engines are built "Bad Ass", and they'll make the power we say they'll make and hold together like they are supposed to hold together! They are built strong and designed to withstand the kind of abuse that you want to put it through. After all, it's our reputation and ass on the line! You think Paco down in mexico building crate engines gives a rat's ass about your engine? Well we do!
Now you can see, there are lots of options that dictate how strong an engine will be, how much power it is capable of handling, and what it will cost, and it usually doesn't have anything to do with how much power it is capable of making. Always remember, it's the quality and strength you're paying for... not the horsepower.