well, that theory is based on using stock pistons. if you lower the compression of the GSR motor you could run (in theory) however much boost you want. same with the LS. the former owner of a local shop in cockeysville (mike dowell) was pushing 7xx wheel on his built GSR @ 30psi, and a friend of mine that worked with me at acura had a built h22 pushing 740 but i dunno how much boost.