Sometimes less is more......And here's why!!

Talked to a guy who'd just bought a 1969 Mustang Mach 1 the other day. He wanted to hot rod it, so his plan was to put the numbers matching 351W on a stand in his garage and buy a Ford Racing crate motor. I thought this was sound thinking, as now he could drive it like he stole it and not worry about throwing a rod out the side of a hard to find block. But he was a little confused. He'd called a Ford dealer to inquire about the crate engines, and the parts guy recommended he buy the 362 hp 351W crate motor. He couldn't understand why the parts guy was trying to steer him away from the 385 hp 351W crate motor or the 400+ hp 392 stroker. When I told him the parts guy was giving him good advice, he was more confused. "Why would less power be better?" He asked. I explained that the 385 hp motor had a very hot cam and a Nascar-style single-plane Edelbrock "Victor Jr" intake manifold that only made power from 3,500-8,000 rpm. The factory owner's manual for these engines recommends 4.56:1 gears!! This engine makes very little power below 4,000 rpm, and is not really a street engine. It's more designed for circle-track racing or drag racing. By contrast-the 362 hp motor-while only being down 23 hp on the top end-is much more streetable. It's cam makes 14 inches of vacuum at idle as opposed to 10, and the intake manifold is a dual-plane Performer RPM with a power range of 1,500-6,500. The owner's manual for this engine recommends at least 3.50:1 gears. I explained that the "lesser" engine would still go plenty fast, but would Idle smoother, work with all the cars accessories, and work better with an automatic transmission if he had one. I also explained that it would have the low-end, tire boiling torque he was looking for, rather than being "peaky" and only having power on the top end. I told him-you get to the point of diminishing returns. If your a handgun shooter-a .38 is very pleasant to shoot and is certainly  powerful enough to put down an attacker if your life was in danger. A .357 Magnum has more recoil, but is still manageble for most people, and has enough power to kill a deer or a wild boar. "Dirty Harry" movies aside-a .44 Magnum can shoot clean THROUGH a deer and penetrate an automobile engine block. However, it's recoil is so fierce that it's virtually unshootable for all but the most expert shooters and the large frame needed to control the massive recoil is so heavy, that their hard to conceal and very uncomfortable to carry for more than about five minutes. Thus if you were a cop, or had a concealed-weapons permit a .38 or .357 would be a much better weapon to carry on a daily basis than a .44 Magnum, even though they have less stopping power. Conversely, if you were a park ranger in Alaska and could carry the gun openly, and encountered grizzly bears, polar bears and mountain lions fairly regularly, The big, bad, .44 is the only way to fly. Same with cars-a street machine needs a different style engine than an all-out racer. Here's a perfect example of the less-is-more theory. Let's say your building a 400 Pontiac. The Edelbrock Performer package includes a dual-plane manifold and a cam with 278 / 288 duration and .420 / .442 lift. With 72cc heads and headers this combo makes 387 hp and 439 lbs ft of torque. Plenty stout for a street engine that has 15 inches of vacuum at it's 750 rpm idle and works with a stock torque converter, and stock gears like 3.08:1. The Performer "RPM" package includes a taller manifold and a much hotter cam-an exact replica of the factory RAIV grind. 308 / 320 duration and .470 lift. With the same heads and headers this combo made 422 hp and 441 lbs ft of torque. A difference of 35 hp and 2 lbs of torque. However this engine only made 10 inches of vacuum at a 1,000 rpm idle, and most of the power increase was above 4,500 rpm. You can do the math-your trading quite a bit of low-end and mid-range torque for top-end rush. There's a reason the RAIV engine was only available with 3.90:1 or 4.33:1 gears!!  The point here is-let's say they were both installed in '70's Trans-Ams-yes the "RPM" package would be faster in the 1/4 mile provided you had 3.73:1 or stiffer gears and a four-speed or a high-stall converter. The Performer Package would idle smoother, get better gas mileage, and still rip the tires as long as you wanted to stay on the throttle, and probably only run 3 tenths slower in the 1/4. Remember-it's only down 35 hp from the "Big Dog". This is what I mean by the point of diminishing returns. That's where, yes you can go faster-but at a big penalty to idle quality, low-end torque and driveability, freeway cruising rpm, and fuel economy. If your building a racer or show car then do anything you want. But if you want to drive the car at all-bigger is not always better, so be careful when chasing every last ounce of speed. Mastermind