I'm going to use ARP Head-Studs for my heads/cam install......but I was wondering if anyone had ever broken a stock head bolt during the torque/twist procudure that is used on the stock head bolts during install, it seems that 150º of rotation after an initial torque of 22 ft/lbs is ALOT of twist on a bolt

 

i thought it was 90deg according to gm all data.

 

The "official" GM method is two sequential rotations of 74.5º each for a total of 149º.....most people doing their own install do a 90º and a 45º because it's easier to keep track of

 

Yep a co-worker had 1 snap off at the front on a suburban. Broke off clean in the block. Had to remove the head, take the truck to a machine shop where I think they just tacked on a bolt and got it out.