Well I do have them installed on my GT. My boy, Brian Robak did the install - since I was way too chicken to try it by myself.

From watching him do it, it was not that difficult. Time consuming? Yes. 3 hours total.

Pretty much most of the time is spent removing everything off of the car but I would say the actual rocker install only took about an hour (maybe less).

Some of the major points that needed to be removed - dog bones on front, alternator and then valve covers - the rears was where the install slowed the most.

Having an inch/pound torque wrench would be the most accurate - but using a foot/pound one and good judgement should be okay as well.

Good luck