Short of stroking the 360,there is only one way to increase the STATIC compression ratio, and that is to reduce the combustion chamber size.
There are however several ways to do that, none of which are cheap.
There is another way to some performance, and that is to increase the DYNAMIC compression ratio. And that is where the custom cam comes in, that I earlier mentioned. It'll cost you a few bucks more than an off-the-shelf cam,but if chosen carefully, can make your stocker scoot pretty good.
