Compression

With answers like that, it's hard to add 2 cents. Car Craft has a write up on it. It doesn't add to much to the answers given, but goes further in detail.
You'll find it in the "Whats your problem" tech question and answer section. (Page 69 starts the section. flip 2 pages for the compression question.)

A few issues back, they also did 2 small block Chevy build ups (No surprise there) that were different in many respects (350 vs 383 stroker) that showed how to get X amount of HP out of them. The stroker engine was a low 8-1 that wacked out something like 500 HP on low octane while the 350, did the same on high octane.
The purpose of the build was to show you the power of strokers, head choice, cam choice and posibiltys and choices that can still net big power.
If you look past the "Chevy" label, you can see that it still applies to any engine.
A little creative thinking and you could do the same.
Careful selection of parts and how they'll work is the key.