"Stealth" modifications that can really increase performance!

I get a lot of people asking me how can I make my car go faster and still look stock?  Here's a list of "hidden" modifications that can drastically increase performance. I'll try to start with the cheap and easy ones and progress to the more time-consuming and expensive ones. # 1. Ignition. You'd be amazed that some of the musclecars running around will even start, much less run decent. They'll have the timing way advanced or too slow, the vacuum advance unplugged, the points closing up, the rotor burned, and the wires so old they snap in two if you try to pull one off to check a plug. Make sure the timing is right, that the points and condenser are new and set right, and the cap and rotor and wires also need to be replaced if they haven't been in the last 30,000 miles. Petronix and other companies make electronic ignition conversions that fit under a point-type cap, if you want to go that way. If you drive like grandma on prozac, then go a range or two hotter on the plugs and change them to the recommended heat range if you take a weekend trip to the drags. Pay attention to what tuners say about your particular engine. For example, I had the strongest 403 Olds / Trans-Am anyone had ever seen, and it was the plug gap that did it! I gave it the Herb Adams VSE "Fire-Am" treatment-headers and real dual exhausts, and a Holley Street Dominator aluminum intake manifold. The engine had noticabely more power and torque, but just like the stocker, it started wheezing around 4,400 rpm and was all done in by 4,700. I noticed the recommended AC plug was an R46SZ-an .080 gap plug. This was done for emissions- a longer spark burns cleaner. But even the mighty GM HEI couldn't jump .080 at high rpm. Pre-1975 Olds engines used the R45S AC plug- a .040 gap. After changing to the .040 gap plugs, the engine pulled hard to 5,400 rpm!! This made a huge difference in performance. Which brings up....# 2. Induction.  The first thing the average idiot does as soon as his car fouls a plug is start screwing around with the carburator(s).  Don't. Make sure the float is set properly and that the accelerator pump is getting full range of motion. Make sure there's no restriction in the linkage, that your getting full-throttle opening and have a fresh filter. Jetting can vary due to engine type and carb type, but this is good basic advice regardless of the car. As for intake manifolds, they can make a big difference in performance. GMPP makes a cast-iron version of the original Z/28 / LT-1 Small-block Chevy intake. This is an excellent choice for racers whose class rules mandate an iron manifold, or for street rodders that want an extra 30 or 40 hp while looking stock. Pontiacs from 1967-74 have an excellent stock intake. However, the 1975-79 models have a restrictive throttle opening which limits power above 4,000 rpm. If you have one of these engines, I'd switch to the earlier factory manifold or get an Edelbrock Performer and paint it blue. That's a good stealth trick regardless of make-paint an aftermarket intake the factory color. # 3. Gears. Unless your car came stock with gears in the 3.08 -4.10 range- You need to change gears. This is the problem with most '70's cars-they have salt-flats gearing like 2.56:1.  Something in the 3.23 to the 3.73 range will drastically improve performance.  # 4. In the early '60's Chrysler found more performance not in the engine, but the transmission.  If you have an automatic, a shift-improver kit and a mild converter will drastically improve 0-60 times. By mild I mean around 2,000 rpm. This will give 500-800 more rpm stall than most stock converters and not hurt driveability. A 3,000 on up stall converter isn't necessary unless you have a stompin' engine with a really big cam.  # 5. Cylinder heads. Luckily, modern, free-breathing heads will bolt on to older blocks. I.E.- "Vortec" heads for a small-block Chevy and "Magnum" heads for small-block Mopars. Or you can get aftermarket aluminum heads for just about anything and paint them the factory color.  #6. Stroker cranks. I put these last because they require pulling the engine and tearing it down. You can make a 302 Ford into a 347, or a 350 Chevy into a 383, a 360 Mopar into a 410, and dozens of other combinations. All other things being equal, more cubes means more power. On the other hand, yes, it's possible to get 454 inches from a small-block Chevy, but wouldn't it be easier and cheaper to just buy a 454 either MkIV or V?  Anyhow, hope these tips help out. Mastermind