cam gears can be used to dial out overlap on a dyno

the amount of boost you can run on a "built block" is determined by intercooler capability and fuel setup. if you run big injectors and solid intercooling than you should have no worries about detonation.
this is also very dependent on tuning.

id say the block itself would be safe to over 13 psi. thats a ballpark figure too.
higher boost doesnt necessarily mean danger to the motor, if the motor is built correctly.

again...detonation can destroy any motor, built or not. tuning and fuel management are the 2 important things for safety of the engine.

~boom