Giant chrome blowers and shatter-the-earth exhaust rumble is a great way to impress friends and influence people, but many times such overt displays of horsepower are either a liability or outright forbidden. Fortunately, the road to making a small block Chevy look stock while making absurd amounts of power is well-trodden, and there is plenty enough inspiration to go around.
Increasing cubic inches with a stroker crankshaft is one sure way to disguise you engine’s performance potential. Modern aftermarket engine blocks like those made by dart make it possible to squeeze big-block cubic inches into your small-block. Many can go to 427 cubic inches, and some can allow you to go as big as 454 within the stock small-block’s dimensions.
The trick to keeping your big-inch small-block stealthy is to keep the thumping idle to a minimum with a small cam and to use fairly quiet mufflers. An intermediate X-pipe will smooth out exhaust pulsation and make power at the same time.
A coat of paint and some fake Original Equipment stickers will do wonders for your stealth mission. Simply smoothing down your engine block and painting both it and the cylinder heads stock Chevy Orange will give the impression of originality, but some air-cleaner stickers will bring it home.
A word of warning here: even the greenest green-horns can tell the difference in sound between a 327ci engine and a 427. Keep your stickers within about 50 ci, and no one will be the wiser.
Hiding nitrous systems has become something of an art form in the sleeper set. However, don’t think that anyone will be fooled by those 3/4-inch diameter rubber “vacuum tubes” going into your air filter. That won’t cut it anymore.
The savvyest of racers have begun to mount their multi-point nitrous systems underneath the intake manifold and using angled injectors that allow them to spray perpendicular to the runner bottom. Chevrolet motors use a fully enclosed intake, so you’re going to have to drill a couple of holes in the back of the block to run lines, but there’s nothing vital to worry about hitting.
One word of warning: the intake valley of your engine gets tremendously hot, so consider the use of a heat-insulating valley-pan mandatory. If you choose to take this approach, bear in mind that driving around with your nitrous system armed all the time while exposed to 200-degree heat is an explosion waiting to happen. Purge the system when not in use, and save the nitrous for when it counts.