[HSSS427]

I've scanned a lot of the posts here, and read several books and articles, but am still trying to understand what the basic "rules" are that guide how to determine various cam specs. Seems that most of the articles describe how a cam works, what the various definitions are, but don't really tell you how to determine correct lift, duraction, lobe separation, advance, etc other than to "call a cam manufacturer." As such, I would like to get some commentary going on what to consider to answer the following types of questions. In lieu of this, could we attach a wire to Keith Craft or George Anderson's brains and have it produce a print out?

1. How do you determine the appropriate amount of intake lift, exhaust lift? I've read something that lift should at least be .25 of the diameter of the valve. Is that correct and what factors would cause you to go with less, or more lift? ie type of use, rpm range where you want most HP, or most Torque?

2. What are the key factors that determine the appropriate duration? When do you want more, and when would you want less?

3. What factors drive determination of correct amount of overlap?

4. How do you determine how much advance?

5. How do you determine appropriate lobe separation?

6. Other key rules or questions I've missed

7. Best books, sites or articles for answering the above

In short, if I know my engine type, CC size, valve sizes, tranny, gears, carb, intake, desired use and rpm range, and velocity of an unladen sparrow, how do I then determine the right cam specs.

My situation, for use as an example is as follows:
- 427 side oiler, cast iron block, .030 overbored
- Shelby American aluminum heads w 82cc chambers, 2.25" intake valves, 1.75" exhaust valves
- Aluminum police interceptor medium rise intake
- Demon 750 cfm double pumper carb
- MSD 6AL electronic ignition
- Tremec 5 spd tranny
- 3.54 rear end
- Primarily street use
- Run 93 octane premium pump gas
- Usual rpm range 1500 - 5000

Trying to do more than just pick a cam here, as I'm also on the pursuit of higher knowledge - which isn't very high given where I'm starting from ;-)

Look forward to being enlightened!
Thanks!
Scott