sbsrkh

iTrader: (28)

That's what I was wondering too?

If its turning over hard enough to twist off that bolt something is wrong. Like others have said, take the rockers off if there is a questions of piston/valve contact. No rockers, no chance they could hit.

JLD58

Dude, you are done. If you broke the head off of that bolt trying to turn the crank that means there is a serious problem because there should be very little resistance in the rotation of the crank. You must have hit a valve with a piston at some point because that is all that could have locked up the crank enough for you to be able to break the head off of a bolt that large. Now you either need to pull the heads yourself to asses the damage yourself or take it somewhere where they can do it for you.

eallanboggs

iTrader: (1)

Stop and think about how much force it takes to break that crank bolt off. More than is required to bring it to the normal specified torque setting which is a ton. If you are in a situation where a fastener requires more force than is normally required(like the force to snap off a crank pulley bolt) to turn it STOP! Don't go any further until you have figured out why you need that much force. As a matter of fact you might do yourself a favor by going backwards a few steps to discover what caused this predicament in the first place. Some of these things are(or should be) learned in shop class in high school or while working with dad in the garage. If you skip over these baby steps and try to skip to straight to doing cam swaps on a GENIII you can expect trouble. There is no substitute for experience. Using a tutorial like LS1HowTo assumes a certain still set and just knowing how to pick up a wrench isn't it. You need to know a lot more

Troux

iTrader: (4)

...which is why my next step is trying to get it to a shop.

vettenuts

iTrader: (4)

What exactly is installed in the motor now? Make sure the rockers and pushrods are out as well as plugs.