We have never had any problems with the block and the head studs or head gaskets, and have been running it since 2006 boosted, and naturally aspirated between 1999 and 2006. Last summer we had max of 23 psi in the first gear and 20 psi in high gear, has been pretty much the same all the time since the first summer. We have been 144 mph at best at 1/8 mile weighing 3600.