Wayne
Active member
incredibly strong. i think they are safe to over 700 , they are a true 4 bolt per cylinder, no guarantees, but so far much safer than a 6.4, and WAY safer than a 6.0 or 7.3 .
Are you running stock head bolts until a gasket blows, or did you already stud your heads? I'd love to know who's got the most power on 6.7 stock head bolts. It's hard to figure out when certain parts are justified when every big built truck just has a ton of parts thrown on it for preventative purposes without quantifying the maximum safe level of each stock component.