Iron fists, velvet gloves....."Stealth" mods.....re-visited......

A lot of people ask "How can I make more power for my musclecar and still look stock?" I touched on this once before-but it's worth revisiting-I've been asked several times in the past few weeks. The answer is not always more power; sometimes mechanical advantage is huge. Anyhow-assuming you have another engine-or don't care about modifying the one in the car-here's the best tips. # 1. Increased Displacement. The old adage "There's no substitute for cubic inches, except cubic dollars" is still true. There's stroker crank and rotating assemblys available to turn a 350 Chevy into a 383, a 302 Ford into a 347, a 351 Ford into a 392, a 360 Chrysler into a 408, a 400 Pontiac into a 467, a 400 Chrysler into a 451, a 454 Chevy into a 496, a 390 Ford into a 447, a 440 Chrysler into a 505. All other things being equal, the larger engine will always make more power and torque. And no one will know just looking at the engine. # 2. Camshaft. A cam change can add as much as 100 hp depending on application. But you have to be careful not to overdo it. Let's say you have a 400 Pontiac and want to put a "Ram Air IV" cam in it. If the 400 in question is in say-a '67 GTO and has 10.75:1 compression, a 4-speed, and 3.55:1 gears-it will really rip. Especially from 2,500-6,000 rpm. If the 400 is in a '77 Trans-Am with 7.6:1 compression, an automatic, and 2.56:1 gears-it won't idle, it'll run like crap, and have LESS power under 4,000 rpm than the stock cam did. See what I'm saying? Also-larger engines can tolerate more "cam" without ill effects. Here's an example-The old standby-for small-block Chevys-the "350 hp" 327 Corvette cam. This cam has 224 duration ( @.050 ) and .447 lift. It would absolutely ruin a 305. It would pretty work good in a 327 with a 4-speed and 3.73:1 gears, better in a 350 with a 4-speed or an automatic with 3.42:1 gears, and would be really sweet in a 383 / 400 even with an automatic and 3.08:1 gears. It's best to err on the side of caution when selecting a cam, especially if you have an automatic transmission. The reason is with a manual-Idle quality isn't nearly as important-with an automatic you need your idle speed to be 600-800 rpm. Any more than that, and the car will try to "creep" ahead at a stoplight-escpecially with a stock torque converter. With a stick-even if the engine idles at 1,000 rpm or more-the driver can launch at any rpm he desires by manipulating the clutch.  Most cam catalogs-give good guidelines-like "Works with a stock torque converter" or "Needs 2,500 rpm converter and 3.70:1 gears" etc. But a cam swap is a big power maker no one can see. # 3. Carburator. Many early musclecars have Carter AFB's that were only 500 or 625 cfm. Edelbrock Performer carbs are basically an updated AFB, and they are available in 750 and 800 cfm versions. Especially on larger engines-like a 389 / 421 Pontiac, 409 Chevy, 390 / 406 Ford-the larger carb can make as much as 25 hp and 30 lbs more of torque. The Carter AVS that came on many Chrysler vehicles only flows about 585 cfm. Especially on a 440-but even a 340 or 383 would really "wake up" with an 800 cfm Edelbrock Thunder AVS.  # 4. Mechanical advantage. Gears can make a huge difference. For example most '87-93 Fox "5.0" Mustangs-either 5-speed or automatic-came with 2.73:1 or 3.08:1 gears. Before I started modifying the engine-I'd swap in some 3.73:1 gears. You won't notice it low gear, but the difference will be HUGE in 2nd, 3rd, and 4th. And it won't hurt fuel economy or cruising RPM on the freeway either. The reason is 5th gear in the T5 is overdrive-.063. 63% of 3.73:1-that knocks the final drive ratio down to like 2.75:1. 4th gear in the Automatics are ovedrive too-something like '078-78% of 3.73is like 3.00:1. Highway cruising will be unaffected-but the diffrence in acceleration through the gears will be amazing. Ditto for the disco-era T/A I mentioned earlier. Swapping the 2.41:1 or 2.56:1 gears for some 3.23:1-3.42:1s will make a massive improvement in acceleration and not hurt drivability.  On the other hand-don't go overboard-if 3.42:1s are great-then 4.11s will make it really rock.....Maybe not-your engine may not have the rev range for 4.10-4.56:1 gears-you could run out of rpm before the end of the 1/4. And no one wants the engine buzzing at 4,000 rpm on the freeway!  So err on the side of caution. But these are all good ways to increase performance and look stock.  Mastermind