I ran these on Comp Cams Camquest dyno program. I used the same setting and just changed the compression from 12:1 to 13:1. The difference was about 15 more hp and 10 more tq. The average differences were only about 4hp and 4 tq. I'm not sure it would be worth adding the extra compression unless you were going to be installing a huge cam and porting the crap out of the intake and heads. Here's the links to the graphs.
12:1
13:1