Cool. According to everything I've read about compression says that you get about a 30HP improvement with each atmosphere you increase compression with no other changes, and mileage improves as well. Detonation is the killer though.
Another way to increase compression is to increase dwell time at TDC. Increasing rod length allows you to do this.
Hot Rod magazine (unfortunately it's no longer free access) was able to build an aluminum head 350 that used a 4.155 inch bore, 3.25 inch stroke and 6.2 inch rods instead of the factory's 4 inch bore, 3.48 inch stroke and 5.7 inch rods. Using this small change in dynamics they were able to increase compression to 11 to 1 and burn not only 87 octane, but they burned the crap you get from Joe's Bait and Gas with no pinging. They put the engine on a dyno and ran it to maximum timing advance with no pinging. The only difference running 8 vs 93 showed was more power, with 87 I think they had 406HO and with 93 they had something like 420HP. I'd not want to mess up a set of aluminum heads, but wonder how well a set of those grooves would work if combined with a long rod engine, might be able to get compression up to 12 to 1 or better off 87 octane. If you could boost an engine from 9 to 1 to 12 to 1 and still run 87 octane, that would mean a considerable increase in power, and of course more power means less fuel needed to maintain a specific level of power. You could even increase the rear end gear ratio without killing acceleration since more power would be available. Might be able to add 10-15MPG with these changes on a small car.