Idk cab on I did mine while I was already in doing hg,s. It shouldn't be too bad though the hardest part is the torque process and its not bad. You have to rotate the motor to a certain crank position torque 4 of them then rotate 180 and do the other 4. Wouldn't be much worse than injector swap or any thing else you have to remove the valvecovers for. I wouldn't be scared to say maybe a 6 to 8 hour job start to finish for the first time, much of that time would be tearing everything else down and putting it back.