Para32
I know in the most general sense, a truck engine is more about Torque and a car engine is more about Horsepower. But horsepower and torque generally come hand in hand at roughly an equal ratio.....ie, a 200 hp engine usually has about 200 ft lb torque. Similarly, a 600 hp engine will roughly have 600 ft lb torque. (not counting a Diesel) I dont think I've ever seen a 200 hp engine w/ 600 ft lb of torque, or the opposite 600 hp with 200 ft lb.

I am guessing that WHERE peak HP and WHERE peak Torque are developed is the most important thing. I have not driven alot of different cars so my 'gold standard' for torque is an old 5.0 liter 302 I had in a mustang or the engine in my Harley....I get that one. Torque.

The opposite end of the spectrum would seem to me to be a WOT Indy car, something that develops its peak HP way up in the rev band. How or why is this engine of any use? For the same size engine do you get maybe 10% more peak HP so long as you keep the revs up?

There is something I am not getting and for many that watch the show a good illustration of this could be useful to many.

I have an old full size OJ bronco and I was considering dropping an old 460 or 429 in it. Would I be better off building the 351 that is in it? I want something significantly more powerful and hopefully stay above the 16 mpg I am getting. A 10 MPG hog would not be that great
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HemiPriest
In my experience small displacement engines have to make power high in the rpm range because they don’t have enough torque to make power lower down. That’s also why those same small engines are good candidates for turbocharging because they make more power when you rev the hell out of them.
If you want a balance of power and fuel economy, I would suggest a rebuild of the 351 between the frame rails with a few economical performance upgrades to also increase efficiency. 
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cosmicfrog
Generally, you get either torque or horsepower. They are interrelated as torque is horsepower times movement. I don't remember the formula as I've been out of school for several years. A larger bore will give you more low end torque but fall flat at high rpms. A smaller bore will really put out at high rpms but is a dog off the line.

An example, a friend kept after me to race when I rode sport touring bikes. He had a 1200 cc Harley. I had 1000 cc's in a Kawasaki Concours. It took a bit to get it together as I told him I don't race for funsies. I absolutely won't race in town as it puts others at risk. He left me off the line. We were racing a stretch of road that is right at a mile long. After about 1/8 of a mile, I was catching him and then pulled away as I got up the power band. At 1/4 mile we were nose and nose and after that I pulled farther away as his engine ran out of breath but mine was doing better. Peak power was at 9500 rpm and on the road, the bike was in its sweet spot at 80 mph.

Had we raced on a 1/8 mile track, he would have probably beat me unless he missed a shift. At 1/4 mile, it would have been close. Longer than that, the larger bore ran out of breath.
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HemiPriest
I think you have that backwards cosmic. Horsepower is a mathematical computation based on torque. If I’m not mistaken you take the torque measured at any rpm (but peak is preferred also if I’m not mistaken) you multiply that by the current rpm and then divide by 5252. Again I’m hazy on actual figures but I know I was taught somewhere that horsepower is a figure while torque is a measurement. That’s also why you tend to find the horsepower and torque lines cross on a dyno sheet because that’s where the computation intersects. 
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cosmicfrog
It's been so long since I worked with the math in school (nearly 50 years) you may be right. While I can get anything running, I never was much of a mathematician. When I was first learning my numbers, somebody developed a "New Math" to justify their research grant. It was excellent with people who already worked with math but was lousy for people trying to learn math. 
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