I was wondering wtf that screw was all about until I looked it up. Pretty lame that the 7 bolt uses a screw. 6 bolts have a bolt just like the rest of the holes.
Here's a helpful link I found:
http://www.dsmtuners.com/forums/cyli...need-info.html
Why not spray some paint stripper on the block beforehand? The aircraft stripper I used worked great.