How to look "Stock"...But be badass....

I get a lot of people asking me how can they keep their musclecars looking stock, yet still get killer performance. It's possible-but the key words are "looking stock."  There's several areas where you can stealthily gain large chunks of hp and torque and mechanical advantage.  # 1. Increase displacement. The old saying-"There's no substitute for cubic inches, except cubic dollars" is still true. However-here's where you have to be willing to compromise a little. I can fully understand not wanting to bore and stroke and then abuse a numbers-matching block. If that's the case-then put the precious numbers-matching original engine on a stand in a plastic bag in your garage. You now have two choices-you can buy a high-performance crate engine-GMPP, Blueprint Engines, Ford SVT, Mopar Performance,Edelbrock, and other companies all sell mega-hp crate engines ranging from 302 to 572 cubic inches. That's the easy-and expensive way. The crate engines start at $4,000 and go up to $15,000 plus depending on how radical you want to be. You can buy anywhere from 300 to 800 hp, the only limit being your wallet and imagination. If you can afford to do that-then write that big check and have fun. If your like to rest of us-you may have to get a junkyard engine and re-build that. The upside is the aftermarket is full of stroker crank kits to turn a 302 Ford into a 347 or a 363, s 350 Chevy into a 383, a 351W Ford into a 392, or a 427, a 360 Mopar into 408, a 400 Mopar into a 451, a 400 Pontiac into a 433 or 461, a 454 Chevy into a 482 and a 460 Ford into a 514. I'm sure theres others I missed, but you get the point. Which is all other things being equal-whether it's a 302 / 347, 350 / 383, 400 / 461 or whatever-the larger engine is going to make substantially more power and torque with the same equipment. # 2. Cylinder Heads. A couple of perfect examples-Small-Block Chevy "Vortec" heads breathe better than any other factory head and many aftermarket ones. Last time I checked you could buy a brand-new complete pair from Scoggin-Dickey for $650. That's a screaming bargain. Most machine shops charge more than that to do a decent valve job on your old heads. You will need a Vortec bolt-pattern intake, but GMPP, Edelbrock, Weiand, and Holley have got you covered. Granted, an aluminum intake won't look stock-( you could paint it the factory color to be stealthy ) but the Iron heads will and the hp and torque gain will be huge-40 hp from the heads and another 25-30 from the intake. The same goes for small-block Mopar "Magnum" heads. They breathe better than any factory head and many aftermarket ones, and they will bolt up to older ( pre-'92 ) blocks, and Edelbrock makes "Magnum" compatible intakes. Ford "Explorer" heads breathe better than a lot of factory and aftermarket heads for the 302. Late '70's "6X" heads breather better than any Pontiac head except the vaunted Ram Air IV / 455HO / 455SD heads. You may have to read up on certain engine lines, and maybe consult a Hollander interchange manual ( the "Bible" that junkyards use to know which parts are compatible with multiple applications ) but every manufacturer has certain heads that breathe better than others, and are relatively plentiful in junkyards. # 3. Carburation. A lot of people don't know it-but the Autolite 4bbl on many 289 and even 351W Mustangs only flows about 470 cfm, which really isn't enough even for a stock engine. Replacing that with a 600 cfm Holley or Edelbrock carb will give you a big boost in performance. The Carter AVS that came on most 383 / 440 Mopars from 1966-71 only flows about 585 cfm. A 440 V8 with a 585 cfm carb is like a 250 lb NFL running back trying to run while breathing through a straw. Switching to an 800 cfm Edelbrock Thunder AVS-you'll get by in shows under the "original type" rule-and you'll notice a big bump in oomph. Same with the Carter AFBs that came on '64-66 GTOs, 409 Impalas, and others. They flowed about 500 cfm. Switch to a 750 Carter or Edelbrock.  # 4. Exhaust. Even if you don't want headers or can't run them because of class rules-many musclecars have restrictive stock exhaust systems. A good set of duals with free-flowing mufflers and a balance tube or an x-pipe can free up 25-30 hp even behind stock iron exhaust manifolds. # 5. Camshaft. Here you can make a large amount of extra power that no one can see. The main thing is follow the cam manufacturer's recommendations-their usually spot-on, and especially if you have an engine under 400 cubes with an automatic transmission-err on the side of caution. Larger engines can tolerate more "cam" without ill effects because they generally have more low-end torque to start with, and can afford to lose some-you usually trade some low-end for an increase in the mid-range and top-end. Manual transmission cars can tolerate more "cam" than automatics because idle quality isn't as important and the driver can launch at whatever rpm he desires by manipulating the clutch. For example-the old standby-the "350 hp" 327 Corvette cam for small-block Chevys. This cam would absolutely ruin a 283 or a 305 regardless of transmission. It will work pretty good in a 327 with a 4-speed and 3.55:1 or stiffer gears, great in a 350 with a 4-speed or an automatic and 3.42:1 gears, and be really sweet in a 383 / 400 even with an automatic and 3.08:1 gears. See what I'm saying? # 6. Mechanical advantage. Swapping some 2.73:1 or 3.08:1 gears for some 3.55:1s or 3.73:1s will give you a boost in acceleration without hurting fuel economy or freeway cruising rpm too much. A torque converter with a slightly higher stall speed will help immensely if you have an automatic. But don't go overboard-unless you have something really radical-a converter with a stall speed between 2,000-2,500 rpm is usually enough for most applications. Especially with big-blocks-a converter with 3,000+ rpm of stall speed will probably just give you excessive wheelspin, and have quite a bit of slippage motoring around town. If you actually NEED a 4,000 rpm converter, then maybe your combo is a little TOO radical!!  Hope these tips help everyone out. Mastermind