ive spun a 109 to 7500 rpm never lifted a head.now start moving over 90lbs a minute regardless of rpm and see what starts happening.here is the answer, since i have done,not read about it or heard about it, small cracks from cylinder pressure will start to form and eventually the cylinder gives way,head gets torched,cometic torched,deck torched.i had alot of time on my last 109 so i got another one built the same way i was very happy.however 800+rwhp, 900 to 1000 fwhp these things will happen.hard fill,bigger studs etc you cant get around the fact the cylinder walls will go away and thats if its built right and tuned right.noticed i used cylinder pressure not boost pressure since a killer set of heads lowers the boost pressure, it doesnt change the fact that cylinder pressure is what will kill it eventually