[davesdeville]

Decking the block is usually done to get a good quench distance (piston to head dist.) Depending on the crushed thickness of your headgasket, you'll usually want around zero deck for a tight quench. Or you'd want to run the pistons way down in the hole, like .120, for a very loose quench. In between has a tendency to see detonation problems.

If you want a bit more compression have the heads milled. .040" which is about all I'd be comfortable doing, should get it to about 8.75:1 by calculations (which might be wrong since it's 1am and I should get some sleep.) Still would do well on regular gas, and might net you a dozen ponies or so.