Iron fists, velvet gloves revisited.....

I get a lot of people asking me how can they get serious power from their musclecar and look stock. It can be done, it just takes a little ingenuity. While individual engine lines have nuances that will vary-there are some things that will work across the board regardless of which kind of engine your building. I'll stick to those for this discussion. # 1. Increase displacement. The old saying "There's no substitute for cubic inches, except cubic dollars" is still true. All other things being equal, the larger engine will always make more hp and torque. In some cases it's a no-brainer engine swap-i.e.-swap your 305 Chevy for a 350, or your 307 Olds for a 350 or 403. In others a stroker crank / rotating assembly is the way to go. There are kits to turn a 350 Chevy into a 383, a 302 Ford into a 347, a 351W into a 392, a 360 Chrysler into a 408. That's just the small-blocks. There's kits to turn a 400 Pontiac into a 428 or 455,a 400 Mopar into a 451, a 440 into a 505. There's kits to turn 454 Chevys into a 496. Whether your combo is mild or wild, extra cubes mean extra power. #2. Camshaft. Since no one can possibly know what cam your running ( a lumpy idle will tell the practiced ear it's not stock ) a cam swap is a great "stealth" modification. Larger engines can tolerate more "cam" than smaller ones because usually your trading some bottom-end and mid-range torque for top-end rush. The larger engine having more torque to start with-won't notice the loss as much. For example if you have a 455 Pontiac that has 480 lbs of torque at 2,700 rpm-and your "hot" cam causes it to lose 30 lbs ft at low rpm-guess what? It still has 450 lbs of tire-boiling torque, and you won't notice the supposed "loss". You will notice the big "kick" from about 3,000 rpm on up however! Conversely if you had a late-'70's 350 Chevy that had 280 lbs of torque-and you dropped 30 lbs ft off-idle-you'd definitely notice that!  Manual transmission cars can also tolerate more "cam" than automatics because idle speed isn't as important and the driver can launch at whatever rpm he desires by manipulating the clutch. Using the small-block Chevy as an example-the old standby-the "350 hp 327 Corvette" cam. This cam would ruin a 305. It works pretty damn good in a 327 with a 4-speed and 3.73:1 gears, better in a 350 with 3.23:1s or stiffer either stick or automatic, provided you have a 2,000 rpm+ torque converter, and is really sweet in a 383 / 400 regardless of transmission or gearing. In a 400-this cam will rock even with an automatic, a stock converter and 3.08:1 gears. See what I'm saying?  Consult the cam manufacturer for your engine line. Obviously a cam that's considered "mild" in a 460 Ford would be horrible in a 302 or 351. One that's "super-hot" in a 318 Chrysler will purr like a kitten in a 440. Those are broad strokes-but you get the idea. With small-blocks and cars with automatic transmissions it's better to err on the side of caution.  # 3. Induction. Since stock-class drag racers and circle track racers deal with this-many classes require running a "stock" iron intake manifold, there are several companies that offer ported iron manifolds that will give you a gain of 25 hp and 30 lbs ft of torque. GMPP sells an exact replica of the original Z/28 / LT1 manifold that's good from idle to 7,200 rpm-in cast iron. Some engine lines-Pontiacs and big-block Mopars built prior to '75-have excellent manifolds from the factory. A little port matching to the gasket helps a lot. You can also use an Edelbrock or Holley or Weiand aluminum intake and paint it the factory color. This isn't as stealthy as the iron ones, but the casual observer won't notice. The other thing you can improve on is carburation. For example the Carter AVS that came on most 383 / 440 Mopars only flowed about 585 cfm. They had very crisp throttle response and a strong mid-range-a smaller carb will do that. But they were limited on the top-end. Think-a 440 V8 with a 585 cfm carb is like a 250 lb NFL running back trying to run while breathing through a straw. Fortunately Edelbrock has their excellent 800 cfm Thunder AVS models that would be just the ticket. Ditto for some other cars-pre-'67 Pontiacs and Chevys-early Fords,-many had Carter AFBs that flowed 500 or 625 cfm. Edelbrock's "Performer" line of carbs is an exact copy of the AFB with some modern improvements and are available in 500, 600 ( great for dual-quad applications ) 750 and 800 cfm version. I don't need to tell you that a 409 Chevy or 421 Pontiac will run much better with a 750 / 800 cfm carb than it will a 500 or a 625! The same goes for Holleys. Most concurs shows now allow carbs to be the original "type". Ok-get rid of the 50 year old 735 Holley on your 428CJ and replace with a 780 or an 850. Who's going to look at the casting numbers on your carb?  # 4. Exhaust. Here's where you have to make a big decision. A good set of headers and dual exhausts can be worth as much as 50-70 hp. Super Chevy did a test on a pristine LS6 Chevelle. With stock manifolds it pulled 380 hp on the dyno. ( A little off from the factory 450 hp rating; but back then pre-1972- gross ratings were done with no accessories. The lower net ratings used from 1972 on are more accurate. ) With headers it pulled 451 hp. A gain of 71 hp! And that was the first run. They hadn't yet adjusted the carb jetting to compensate for the opened up exhaust or played with ignition timing or distributor advance curve. With a little tuning they might have gotten an even bigger gain, but the point was made. Personally I would put headers on any car or truck I own where it's feasible. The gain in hp and torque, and usually a small bump-2-3 mpg in fuel economy is too good to pass up. But if you want the total "Stealth" "Stock" look-there are companies that sell ported and extrude-honed iron exhaust manifolds-again luckily for you-catering to the racing classes that require iron exhaust manifolds. Or any competent machine shop could do the ones off your engine. Even with iron manifolds-using 2 1/2 inch pipes, an X-pipe or balance tube and low-restriction mufflers can add as much as 30 hp. # 5. Mechanical advantage. Most '70's cars have salt-flats gearing like 2.73:1. Switching to something in the 3.23:1 to 3.73:1 range will give you a HUGE improvement in 0-60 and 1/4 mile time without hurting freeway cruising rpm or drivability too much. Most automatic cars can use a little more stall speed on the torque converter. Don't go crazy-chances are your engine isn't wild enough to warrant a 4,000 rpm converter and 4.56:1 gears-but a converter with 2,000-2,300 rpm stall speed will work wonders for most applications. # 6. Traction. Most musclecars-especially big-block cars can use larger than stock tires and could use some traction aids. A Pinion snubber is good for leaf-spring cars and Lakewood, Competition Engineering and other companies make bolt-on traction bars for leaf and coil-spring suspensions. You can see traction bars-but they help immensely. As for tires BFG, M&H, Mickey Thompson-all offer drag radials and sticky street tires that are DOT-legal. Hope this helps you "sleeper" builders out!  Mastermind